The trapeziometacarpal joint (TMJ) is the most commonly involved arthritic joint in the hand and is often injected in the outpatient setting. This study assesses the accuracy of TMJ injections.

Six pairs of thawed, fresh-frozen cadaveric upper limbs were placed in the anatomic position. The limbs were randomized to be injected by one of two clinicians (a senior and a junior orthopaedic trainee). The TMJ of these specimens was palpated and injected with 0.5mls aqueous jelly dyed with methylene blue. An independent investigator dissected the specimens and the location of the dye was recorded. A Posterior-Anterior radiograph was then taken to assess the bony anatomy of the joint and graded according to Eaton's classification.

Dye was found inside the joint capsule in 10 (83%) of the 12 specimens. Using Fishers Exact test no significant difference was found between the 2 injectors (p=0.46). The 2 joints where the dye was extra-articular had grade III and IV arthritis, whereas all other joints were graded I.

This study shows that good accuracy of TMJ injection can be achieved using palpation in the earlier stages of TMJ arthritis, when surface anatomy is accurate enough for an intra-articular injection. This is also when synovitis is more prevalent and injections are more relevant. However the failure rate of injections increases as the disease advances.

Total Shoulder Resurfacing (TSR) provides a reliable solution for the treatment of glenohumeral arthritis. It confers a number of advantages over traditional joint replacement with stemmed humeral components, in terms of bone preservation and improved joint kinematics.

This study aimed to determine if humeral reaming instruments produce a thermal insult to subchondral bone during TSR. This was tested in vivo on 13 patients (8 with rheumatoid arthritis and 5 with osteoarthritis) with a single reaming system and in vitro with three different humeral reaming systems on saw bone models. Real-time infrared thermal video imaging was used to assess the temperatures generated.

Synthes Epoca instruments generated average temperatures of 40.7°^C (SD 0.9°^C) in the rheumatoid group and 56.5°^C (SD 0.87°^C) in the osteoarthritis group (p = 0.001). Irrigation with room temperature saline cooled the humeral head to 30°^C (SD 1.2°^C). Saw bone analysis generated temperatures of 58.2°^C (SD 0.79°^C) in the Synthes (Epoca) 59.9°^C (SD 0.81°^C) in Biomet (Copeland) and 58.4°^C (SD 0.88°^C) in the Depuy (CAP) reamers (p=0.12).

Humeral reaming with power driven instruments generates considerable temperatures both in vivo and in vitro. This paper demonstrates that a significant thermal effect beyond the 47°^C threshold needed to induce osteonecrosis is observed with humeral reamers, with little variation seen between manufacturers. Irrigation with room temperature saline cools the reamed bone to physiological levels, and should be performed regularly during this step in TSR.

Total Elbow Replacements are indicated for pain and disability in patients with rheumatoid and osteoarthritis of the elbow. The quality of the cementation has been specifically studied and shown to be directly related to the clinical outcome and implant survival.

Approximately one-fifth of patients are not satisfied with total knee arthroplasty (TKA). Preoperative variables associated with poorer outcomes are severity and chronicity of pain and psychological disease, which may present as anxiety and depression. It is unclear whether this is constitutional or the result of knee pain. To address this, we explored the association of anxiety and depression with knee disability before and after TKA.

Forty patients undergoing TKA completed Hospital Anxiety and Depression Scale (HADS) and Oxford Knee Scores (OKS) preoperatively and at three and six months postoperatively. Both were elevated preoperatively and improved significantly post-operatively (P<0.001). The severity of preoperative anxiety and depression was associated with worse knee disability (coefficient −0.409, p=0.009). Postoperatively reduction in anxiety and depression was associated with improvement in knee disability after three (coefficient −0.459, p=0.003) and six months (coefficient −0.428, p=0.006).

The difficulty in interpreting preoperative anxiety and depression and the outcome of TKA is establishing whether they are the cause or effect of pain in the knee. As anxiety and depression improves with knee pain and function, this study suggests that knee pain contributes to the psychological symptoms and that a successful TKA offers an excellent chance of improving both.

We have prospectively followed up 191 consecutive primary total hip replacements utilising a collarless polished tapered (CPT) femoral stem, implanted in 175 patients between November 1992 and November 1995.

At a mean follow-up of 15.9 years (range 14 – 17.5) 86 patients (95 hips) were still alive (25 men and 61 women) and available for routine follow up. Clinical outcome was determined from a combination of the Harris (HHS) and Oxford (OHS) hip scores. Radiological assessment was with antero-posterior radiographs of both hips and a lateral radiograph of the operated hip. The radiographs were evaluated using well-recognised assessment techniques.

There was no loss to follow up, with clinical data available on all 95 hips. Five patients were too frail to undergo radiographic assessment, therefore radiological assessment was performed on 90 hips (95%). At the latest follow-up, the mean HHS was 78 (range 28 – 100) and the mean OHS was 36 (range 15 – 48). Stems subsided within the cement mantle, with a mean total subsidence of 2.1mm (range 0.4 – 24). Higher grades of heterotopic bone formation were significantly associated with males (p<0.001) and hypertrophic osteoarthritis (p<0.001). Acetabular wear was associated with increased weight (p<0.001) and male sex (p=0.005). Amongst the cohort, only 1 stem (1.1%) has been revised due to aseptic loosening. This patient required reaming of their canal prior to implantation, as a result of a previous femoral osteotomy. The rate of stem revision for any cause was 7.4% (7 stems), of which 4.2% (4 stems) resulted from infection following revision of the acetabular component. Twenty patients (21.1%) required some sort of revision procedure; all except 3 of these resulted from failure of the acetabular component. Cemented cups had a significantly lower revision burden (2.7%) than Harris Galante uncemented components (21.8%) (p<0.001).

The CPT stem continues to provide excellent radiological and clinical outcomes at 15 years following implantation. Its results are consistent with other polished tapered stem designs. Cup failure remains a problem and is related in part to inadequate bearings and biological abnormalities.

We prospectively followed 191 consecutive collarless polished tapered (CPT) femoral stems, implanted in 175 patients who had a mean age at operation of 64.5 years (21 to 85). At a mean follow-up of 15.9 years (14 to 17.5), 86 patients (95 hips) were still alive. The fate of all original stems is known. The 16-year survivorship with re-operation for any reason was 80.7% (95% confidence interval 72 to 89.4). There was no loss to follow-up, with clinical data available on all 95 hips and radiological assessment performed on 90 hips (95%). At latest follow-up, the mean Harris hip score was 78 (28 to 100) and the mean Oxford hip score was 36 (15 to 48). Stems subsided within the cement mantle, with a mean subsidence of 2.1 mm (0.4 to 19.2). Among the original cohort, only one stem (0.5%) has been revised due to aseptic loosening. In total seven stems were revised for any cause, of which four revisions were required for infection following revision of the acetabular component. A total of 21 patients (11%) required some sort of revision procedure; all except three of these resulted from failure of the acetabular component. Cemented acetabular components had a significantly lower revision burden (three hips, 2.7%) than Harris Galante uncemented components (17 hips, 21.8%) (p < 0.001).

The CPT stem continues to provide excellent radiological and clinical outcomes at 15 years following implantation. Its results are consistent with other polished tapered stem designs.

We studied, ten patients (11 elbows) who had undergone 14 allograft-prosthesis composite reconstructions following failure of a previous total elbow replacement with massive structural bone loss. There were nine women and one man with a mean age of 64 years (40 to 84), who were reviewed at a mean of 75 months (24 to 213). One patient developed a deep infection after 26 months and had the allograft-prosthesis composite removed, and two patients had mild pain. The median flexion-extension arc was 100° (95% confidence interval (CI) 76° to 124°). With the exception of the patient who had the infected failure, all the patients could use their elbows comfortably without splints or braces for activities of daily living. The mean Mayo Elbow Performance Index improved from 9.5 (95% CI 4.4 to 14.7) pre-operatively to 74 (95% CI 62.4 to 84.9) at final review.

Radiologically, the rate of partial resorption was similar in the humeral and ulnar allografts (three of six and four of eight, respectively; p > 0.999). The patterns of resorption, however, were different. Union at the host-bone-allograft junction was also different between the humeral and ulnar allografts (one of six and seven of eight showing union, respectively; p = 0.03).

At medium-term follow-up, allograft-prosthesis composite reconstruction appears to be a useful salvage technique for failed elbow replacements with massive bone loss. The effects of allograft resorption and host-bone-allograft junctional union on the longevity of allograft-prosthesis composite reconstruction, however, remain unknown, and it is our view that these patients should remain under long-term regular review.

Clinician expectation and anatomical studies suggest that the distribution of sensory dysfunction in carpal tunnel syndrome (CTS) should be confined to the thumb, index, middle and half of the ring fingers. We mapped the distribution of disturbance to evaluate the accuracy of these assumptions.

We evaluated 64 wrists in 64 patients with nerve conduction study confirmed CTS. Each patient filled out a Katz hand diagram and we collated the distribution of pain and non-painful (tingling, numbness & decreased sensation) sensory disturbance. Frequency of reporting was analysed; dividing symptoms into thenar and hypo-thenar eminence, distal palm, each digit, posterior hand and forearm.

Non-painful sensory disturbance occurred in all patients. The index finger was the most common location (94%) followed by the middle finger (91%), the distal palm (84%), the ring finger (72%), the thumb (69%), the thenar eminence (63%), the little finger (39%), the dorsal hand (31%), the hypothenar eminence (25%) and the forearm (13%).

Pain was less common, reported in 59% of cases. Pain occurred most frequently over the wrist crease (33%) followed by thenar eminence (27%), the forearm (20%), the middle finger (23%), the index finger (22%), the ring finger (19%), the distal palm (16%), the thumb (14%), the dorsal hand (11%), the little finger (11%) and least frequently the hypothenar eminence (6%)

In CTS sensory disturbance occurs most frequently in the median nerve distribution; however it occurs almost as often elsewhere. An atypical distribution of symptoms should not discourage diagnosis of CTS.

The aim of the current study was to assess the amount of the distal humerus articular surface exposed through the Newcastle approach, a posterior triceps preserving exposure of the elbow joint.

24 cadaveric elbows (12 pairs) were randomized to receive one of the four posterior surgical approaches: triceps reflecting, triceps splitting, olecranon osteotomy and Newcastle approach. The ratio of the articular surface exposed for each elbow was calculated and compared.

The highest ratio observed was for Newcastle approach (0.75 ± 0.12) followed by olecranon osteotomy (0.51 ± 0.1), triceps reflecting (0.37 ± 0.08) and triceps splitting (0.35 ± 0.07). The differences between Newcastle approach and other approaches were statistically significant (p=0.003 vs osteotomy and < 0.0001 vs triceps reflecting and splitting).

The Newcastle approach sufficiently exposes the distal humerus for arthroplasty or fracture fixation purposes. Its use is supported by the current study.

Cement pressurisation in the distal humerus is technically difficult due to the anatomy of the humeral intramedullary (IM) cavity. Conventional cement restrictors often migrate proximally, reducing the effect of pressurisation during arthroplasty. Theoretically with a better cement bone interdigitation, the longevity of the elbow replacement can be improved.

The aim of this cadaveric study was to evaluate the usefulness of a novel technique for cementation.

Eight paired cadaveric elbows were used. The sides were randomly allocated to the conventional cementation group and pressurisation using a foley cathetre used as a cement restrictor. The cathetre was inserted into the IM canal after thorough washout and drying the cavity. The balloon inflated to act as a cement restrictor. Cementation was then performed and the cathetre removed just prior to cement setting. Radiographs of each pair was taken. Each distal humerus sample was cut in 1 cm increments starting from proximal part of the coronoid fossa. The slices were also radiographed to assess cement-bone interdigitation. The area of IM canal and the cement were calculated. The paired samples were compared.

The new technique consistently and significantly achieved a better cement interdigitation into the cancellous bone. The maximum penetration was observed in the proximal 1–3 cms from the coronoid fossa. According to previous studies, this area is the most common part involved in cement failure and loosening.

This study confirms the effectiveness of a foley cathetre as a cement restrictor. The ease of the technique and excellent pressurisation achived support its use.

The aim of this study was to determine patient-reported outcomes after arthroscopic rotator cuff repair with a new knot-free technique.

A questionnaire was completed by 50 patients who underwent an arthroscopic rotator cuff repair with a knot-free technique. Validated questionnaires included the Oxford Shoulder Score (12–60, good to poor) and SF-36 (0–100, poor to good). Patients also completed a 100mm VAS (0–100, good to poor) to rate the following domains: daytime pain, night-time pain, movement, strength, well-being, ability to do ADLs, participation in sports, ability to do leisure activities and whether they felt their shoulder was back to the way it was before the problem started.

The mean length of follow-up was 15 months (range 7–25 months). The mean age of patients was 62 years (range 36–78) and 70% were male. The mean OSS was 22 (SD 10). Mean scores for the 8 domains of the SF-36 were: 74 for physical functioning, 71 for role physical, 66 for bodily pain, 67 for general health, 57 for vitality, 82 for social functioning, 85 for role emotional and 81 for mental health. The mean VAS for the 9 outcome domains were as follows: 16 for night-time pain and daytime pain, 19 for movement, 21 for ability to do ADLs, 22 for well-being, 23 for whether the shoulder was back to the way it was, 28 for ability to do leisure activities, 29 for strength and 33 for ability to participate in sports.

In conclusion, patients reported excellent post-operative OSS with the knot-free technique. The SF-36 revealed that patients had high social and emotional functioning and good physical outcomes were reported on the VAS for pain, ADLs and movement. However, going back to an expected level of sport is not always achievable.

Study Design: This is a retrospective study evaluating the use of BoneSave (Stryker, UK) in posterolateral inter-transverse spinal fusion.

Objectives. To evaluate the clinical outcomes and fusion success rates associated with the use of BoneSave in posterolateral spinal fusion.

Summary of Background Data: Achieving spinal fusion is the guiding principle behind surgical treatment for a range of pathologies of the spine. The use of a substantial amount of bonegraft is often required and autograft, commonly harvested from the iliac crest, represents the gold standard. Morbidities associated with graft harvest and a limited supply of graft material have led to the development of alternatives. BoneSave, a porous tricalcium phosphate-hydroxyapatite ceramic, is one such alternative which has been employed in spinal fusion over the past few years. Despite this the outcomes associated with its use lack research.

Methods: Clinical data was collected retrospectively from the case notes of all patients who underwent posterolateral inter-transverse spinal fusion at any level, involving the application of BoneSave, between June 2003 and January 2005 at Frenchay hospital, Bristol, UK. A postal questionnaire was used to collect the latest follow-up information, with an average follow-up of 46 months. Validated outcome instruments employed included the Short Form 36 and Oswestry Low Back Pain Disability Index. In addition visual analogue scales for both back and leg pain, Patient Global Impression of Change data, work status, persisting symptoms, and patient satisfaction data was collected. Radiological evaluation of fusion was carried out from the most recent spinal radiographs available for each patient.

Results: There were 45 patients in the study group. Qualitative post-operative data was available in 96% and response rate to the follow-up questionnaire was 68.4%. Radiographical evaluation was possible in 67%. Significant post-operative improvements were seen across all outcome measures in the large majority of cases. Successful fusion was achieved in 56.7% of cases.

Conclusion: The clinical outcomes associated with the use of BoneSave are comparable to those available in the literature for more conventional techniques of spinal fusion. The fusion rate was not significantly lower than achieved with other techniques.

Introduction: The severity of symptoms, rate and completeness of recovery after closed treatment of the fractured clavicle has not been fully explored.

Materials and Methods: The severity and duration of pain, analgesic requirements, ability to perform acts of daily living, return to work, driving and sport were recorded along with appearance of the shoulder in 58 patients between one to two years after fracture was recorded. Radiographs were assessed by Robinson’s classification8 supplemented by fracture displacement.

Results: The majority of patients experienced severe pain that required codeine, paracetamol and ibuprofen. 13/58 patients (22%) ceased to experience pain by one month, 35/58 (60%) by three and 48/58 (83%) by six. There was no improvement in the remaining ten patients after six months.

21 patients described difficulty reaching and lifting (36%), 11/36 (31%) digging the garden, 13/58 (22%) were unable to reach between their shoulder blades. Over 90% had no difficulty with feeding (55/58), dressing (50/58), personal toilet (56/58), brushing hair (41/46), hanging up clothes (52/56) or ironing (37/41) but overall 23/58 patients (40%) had some functional restriction 1–2 years after injury. 18/48 patients (38%) returned to work within one month, 39 (81%) by three, and all by six. 28/30 (93%) clerical workers had returned within three months compared with 11/18 (61%) of manual (p < 0.05) 36/42 (86%) sportsmen returned. High impact sportsmen were less likely to resume than low impact or overhead. 38/46 (83%) of drivers returned by three months and all by six.

40/58 (69%) patients noted cosmetic deformity the severity of which was associated with worse functional outcome (p = 0.002). The degree of displacement of the fracture was associated with cosmetic deformity (p = 0.015) and functional outcome (p = 0.025), but the Robinson classification8 alone was not.

Conclusion: The majority of patients with a fractured clavicle perceive a cosmetic deformity and a substantial minority impaired function. There is potential to improve outcome and deformity by reduction and fixation in those with displacement of two or more cortical diameters.

Introduction: Cervical range of motion is affected by a wide variety of pathologies and is routinely measured in clinical assessment of the neck. It is therefore crucial to use a method that is both accurate and reliable but that is also non-invasive and inexpensive. This study assessed cervical range of motion using different methods of measurement, namely the universal goniometer and the cervical range of motion (CROM) goniometer. These methods were then compared with each other. In addition, we were interested in determining whether a single component of neck movement is representative of total cervical range of motion.

Methods: 50 healthy subjects between the ages of 18–87 with no shoulder or spine pathology were asked to perform six active neck movements, flexion, extension, lateral flexion and axial rotation while the movements were measured first using the universal goniometer and then with the CROM goniometer. The CROM goniometer has been shown previously to have excellent validity and reliability. The researchers were trained to use the measuring techniques prior to data collection. All measurements were performed by the same researcher for each subject and the two researchers alternated between subjects.

Results: Comparison between the universal goniometer and the CROM goniometer was performed using Bland and Altman plots. This revealed that 60.6% of universal goniometer readings were within ±5° of the CROM reading; however 31.6% of readings differed by > ±5° and 7.8% differed by > ±10°. The interobserver variance was calculated and there was excellent agreement between the two researchers for both the universal goniometer and CROM goniometer, with an intraclass correlation coefficient of ≥0.80 for every movement. Extension was the most predictive of total neck movement (Pearson coefficient 0.643, p < 0.001). This continues to be the case even when the negative effect of age on range of motion is taken into account.

Discussion: The finding that extension was the most representative neck movement has implications for the assessment of cervical motion. Accordingly, if a single neck movement is measured to represent total range of motion, extension should be used.

The comparison between the CROM and universal goniometer demonstrated that the majority of goniometer readings were within 5° of the CROM result; however, this was not consistently the case. Given that the CROM is a valid and reliable method of measuring neck movement, the inconsistency between the goniometer and CROM can be taken as inaccuracy on the part of the universal goniometer. As the interobserver variance is excellent one can assume that these results are reproducible and that the errors observed are a true reflection of the limitations of the device.

We have reviewed 22 patients at a mean of 30 years (28 to 31) after a whiplash injury. A complete recovery had been made in ten (45.5%) while one continued to describe severe symptoms. Persistent disability was associated with psychological distress but both improved in the period between 15 and 30 years after injury. After 30 years, ten patients (45.5%) were more disabled by knee than by neck pain.

Introduction: The long-term results of 70 Harris-Galante I uncemented acetabular components implanted in 53 patients who were under 50 years of age at the time of their hip arthroplasty are presented.

Methods: Follow up was both clinical, using Oxford and Harris Hip scores, and radiological. Kaplan-Meier survivorship analysis was performed to calculate the survivorship of the acetabular components. Failure was defined as either liner exchange or acetabular component revision due to aseptic loosening, osteolysis, infection or dislocation.

Results: The mean age of the patients at the time of surgery was 40 years (range 19–49 years), with follow up of between 12 and 16 (mean 13.6) years. All patients’ acetabular components were implanted primarily with cemented femoral components. The mean Oxford Hip Score at the end of the follow-up period was 20 out of 60 (range 12–46) and Harris Hip Score 81 (range 37–100).

At the end of the follow up period, 11 of the 70 acetabular components (polyethylene liner or the acetabular shell) had been revised. The cumulative survival was 94.0% (95% confidence interval 88.4–99.7) with revision of the metal shell as the end point, and 84.0% (95% confidence interval 74.5–93.5) with revision surgery of the acetabular shell or liner due to any reason as an end point. Radiologically, 4 patients require acetabular revision and 22 patients had femoral osteolysis in gruen zone 7, indicative of polyethylene failure. This gave a combined revision, impending revision and zone 7 osteolysis cumulative survival of 55.3% (95% confidence interval 40.6–70.0).

Discussion: In contrast to cemented acetabular components which undergo aseptic loosening and give groin pain, high density polyethylene lined metal shells do not give groin pain but cause silent acetabular and femoral osteolysis. The danger time for osteolysis is between 10–20 years, therefore follow up at that time is essential.

This review discusses the causes, outcome and prevention of whiplash injury, which costs the economy of the United Kingdom approximately £3.64 billion per annum. Most cases occur as the result of rear-end vehicle collisions at speeds of less than 14 mph. Patients present with neck pain and stiffness, occipital headache, thoracolumbar back pain and upper-limb pain and paraesthesia. Over 66% make a full recovery and 2% are permanently disabled. The outcome can be predicted in 70% after three months.

To assess the outcome of semi-constrained total elbow arthroplasty (TEA) in osteoarthritis and compare it to the rheumatoid group.

Two groups of patients assessed. In group-one with the diagnosis of rheumatoid arthritis 40 replaced elbows in 31 patients (25 female and 1 male), with average age of 67 (49–82) were reviewed. Group-two consisted of 14 elbows in 14 patients (9 female and 5 male) with post-traumatic osteoarthritis. Average age in this group was 71 (54–84). Mayo elbow performance (MEPS) and Liverpool elbow scores (LES) were used as the outcome measure.

The average follow up for group-one was 53 (20–90) and group-two 60 months (21–103). According to the MEPS 87.1% of patients in group 1 and 63.6% in group 2 had excellent or good outcome (p=0.09). Only one patient from group one and none in group two had the joint revised. No difference was observed in MEPS of group-one (86 ± 17) and group-two (77 ± 24), (p=0.25). Also the LES in the two groups were not different (p=0.85).

The outcome of TEA is satisfactory in both groups. No statistically significant difference was noted in the two groups. The recommendation of TEA in patients with osteoarthritis is supported by this study.

The aim of this study was to review the outcome of semi-constrained total elbow arthroplasty (TEA) in osteoarthritis and compare it to the rheumatoid group. This was performed on a single-surgeon, single-prosthesis (GSB III) series of patients. Two groups of patients assessed. In the first group with the diagnosis of rheumatoid arthritis 40 replaced elbows in 31 patients (25 female and 1 male), with average age of 67 (range 49–82) were reviewed. The second group consisted of 14 elbows in 14 patients (9 female and 5 male) with post-traumatic osteoarthritis. Average age in this group was 71 (range 54–84). All patients were recalled for clinical review. Fresh radiographs obtained and compared to the immediate postoperative images. Mayo elbow performance (MEPS) and Liverpool elbow scores (LES) were used as the outcome measure. Kaplan-Meier survival analysis for the two groups was performed. The average follow up for the first group was 53 (range 20–90) and second group 60 months (range 21–103). According to the MEPS 87.1% of patients in group 1 and 63.6% in group 2 had excellent or good outcome. This different was not statistically significant (p=0.09). Only one patient from group one and none in group two had the joint revised. No significant difference was observed in MEPS of group one (86 ± 17) and group two (77 ± 24), (p=0.25). Also the LES in the two groups were not different (p=0.85) (group one 8 ± 1 vs. group two 8 ± 2). The outcome of TEA is satisfactory in both groups. No statistically significant difference was noted in the two groups. The recommendation of TEA in patients with osteoarthritis is supported by this study.

We have reviewed 70 Harris-Galante uncemented acetabular components implanted as hybrid hip replacements with cemented stems between 1991 and 1995 in 53 patients whose mean age was 40 years (19 to 49). The mean follow-up was for 13.6 years (12 to 16) with no loss to follow-up. We assessed the patients both clinically and radiologically.

The mean Oxford hip score was 20 (12 to 46) and the mean Harris hip score 81 (37 to 100) at the final review. Radiologically, 27 hips (39%) had femoral osteolysis, 13 (19%) acetabular osteolysis, and 31 (44%) radiolucent lines around the acetabular component. Kaplan-Meier survival curves were constructed for the outcomes of revision of the acetabular component, revision of the component and polyethylene liner, and impending revision for progressive osteolysis.

The cumulative survival for revision of the acetabular component was 94% (95% confidence interval 88.4 to 99.7), for the component and liner 84% (95% confidence interval 74.5 to 93.5) and for impending revision 55.3% (95% confidence interval 40.6 to 70) at 16 years.

Uncemented acetabular components with polyethylene liners undergo silent lysis and merit regular long-term radiological review.