Aims

The benefit of a dual-mobility acetabular component (DMC) for primary total hip arthroplasties (THAs) is controversial. This study aimed to compare the dislocation and complication rates when using a DMC compared to single-mobility (SM) acetabular component in primary elective THA using data collected at a single centre, and compare the revision rates and survival outcomes in these two groups.

Aims

This study reports the ten-year wear rates, incidence of osteolysis, clinical outcomes, and complications of a multicentre randomized controlled trial comparing oxidized zirconium (OxZr) versus cobalt-chrome (CoCr) femoral heads with ultra-high molecular weight polyethylene (UHMWPE) and highly cross-linked polyethylene (XLPE) liners in total hip arthroplasty (THA).

Aims

Total hip arthroplasty (THA) is a very successful and cost-effective operation, yet debate continues about the optimum fixation philosophy in different age groups. The concept of the 'cementless paradox' and the UK 'Getting it Right First Time' initiative encourage increased use of cemented fixation due to purported lower revision rates, especially in elderly patients, and decreased cost.

Aims

The Exeter V40 cemented femoral stem was first introduced in 2000. The largest single-centre analysis of this implant to date was published in 2018 by Westerman et al. Excellent results were reported at a minimum of ten years for the first 540 cases performed at the designer centre in the Exeter NHS Trust, with stem survivorship of 96.8%. The aim of this current study is to report long-term outcomes and survivorship for the Exeter V40 stem in a non-designer centre.

Aims

Despite advances in the treatment of paediatric hip disease, adolescent and young adult patients can develop early onset end-stage osteoarthritis. The aims of this study were to address the indications and medium-term outcomes for total hip arthroplasty (THA) with ceramic bearings for teenage patients.

Aims

This combined clinical and in vitro study aimed to determine the incidence of liner malseating in modular dual mobility (MDM) constructs in primary total hip arthroplasties (THAs) from a large volume arthroplasty centre, and determine whether malseating increases the potential for fretting and corrosion at the modular metal interface in malseated MDM constructs using a simulated corrosion chamber.

Aims

The purpose of this study is to examine six types of bearing surfaces implanted at a single institution over three decades to determine whether the reasons for revision vary among the groups and how long it takes to identify differences in survival.

Aims

There is inconsistent evidence on whether prior spinal fusion surgery adversely impacts outcomes following total hip arthroplasty (THA). We conducted a systematic review and meta-analysis to assess the association between pre-existing spinal fusion surgery and the rate of complications following primary THA.

Objectives

Modern metal-on-metal (MoM) hip resurfacing arthroplasty (HRA), while achieving good results with well-orientated, well-designed components in ideal patients, is contraindicated in women, men with head size under 50 mm, or metal hypersensitivity. These patients currently have no access to the benefits of HRA. Highly crosslinked polyethylene (XLPE) has demonstrated clinical success in total hip arthroplasty (THA) and, when used in HRA, potentially reduces metal ion-related sequelae. We report the early performance of HRA using a direct-to-bone cementless mono-bloc XLPE component coupled with a cobalt-chrome femoral head, in the patient group for whom HRA is currently contraindicated.

Ceramic bearings have several desirable properties, such as resistance to wear, hardness, and biocompatibility, that favour it as an articulating surface in hip arthroplasty. However, ceramic fracture remains a concern. We have reviewed the contemporary literature, addressing the factors that can influence the incidence of ceramic bearing surface fracture.

Cite this article: Bone Joint J 2019;101-B:897–901.

Aims

Studying the indications for revision total hip arthroplasty (THA) may enable surgeons to change their practice during the initial procedure, thereby reducing the need for revision surgery. The aim of this study was to identify and describe the potentially avoidable indications for revision THA within five years of the initial procedure.

Aims. This study reports the mid-term results of total hip arthroplasty (THA) performed using a monoblock acetabular component with a large-diameter head (LDH) ceramic-on-ceramic (CoC) bearing. Patients and Methods. Of the 276 hips (246 patients) included in this study, 264 (96%) were reviewed at a mean of 67 months (48 to 79) postoperatively. Procedures were performed with a mini posterior approach. Clinical and radiological outcomes were recorded at regular intervals. A noise assessment questionnaire was completed at last follow-up. Results. There were four re-operations (1%) including one early revision for insufficient primary fixation (0.4%). No hip dislocation was reported. The mean University of California, Los Angeles (UCLA) activity score, 12-Item Short-Form Health Survey (SF-12) Mental Component Summary (MCS) score, SF-12 Physical Component Summary (PCS) score, Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) score, and Forgotten Joint Score (FJS) were 6.6 (2 to 10), 52.8 (25.5 to 65.7), 53.0 (27.2 to 66.5), 7.7 (0 to 63), and 88.5 (23 to 100), respectively. No signs of loosening or osteolysis were observed on radiological review. The incidence of squeaking was 23% (n = 51/225). Squeaking was significantly associated with larger head diameter (p < 0.001), younger age (p < 0.001), higher SF-12 PCS (p < 0.001), and UCLA scores (p < 0.001). Squeaking did not affect patient satisfaction, with 100% of the squeaking hips satisfied with the surgery. Conclusion. LDH CoC THAs have demonstrated excellent functional outcomes at medium-term follow-up, with very low revision rate and no dislocations. The high incidence of squeaking did not affect patient satisfaction or function. LDH CoC with a monoblock acetabular component has the potential to provide long term implant survivorship with unrestricted activity, while avoiding implant impingement, liner fracture at insertion, and hip instability. Cite this article: Bone Joint J 2018;100-B:1434–41

Aims

For this retrospective cohort study, patients aged ≤ 30 years (very young) who underwent total hip arthroplasty (THA) were compared with patients aged ≥ 60 years (elderly) to evaluate the rate of revision arthroplasty, implant survival, the indications for revision, the complications, and the patient-reported outcomes.

Aims

It is important to consider sagittal pelvic rotation when introducing the acetabular component at total hip arthroplasty (THA). The purpose of this study was to identify patients who are at risk of unfavourable pelvic mobility, which could result in poor outcomes after THA.

Aims

The primary aim of this independent prospective randomised trial was to compare serum metal ion levels for ceramic-on-metal (CoM) and metal-on-metal (MoM) bearing surfaces in total hip arthroplasty (THA). Our one-year results demonstrated elevation in metal ion levels above baseline with no significant difference between the CoM and MoM groups. This paper reviews the five-year data.

Aims

To determine the effect of a change in design of a cementless ceramic acetabular component in fixation and clinical outcome after total hip arthroplasty

Aims. We conducted a prospective study of a delta ceramic total hip arthroplasty (THA) to determine the rate of ceramic fracture, to characterise post-operative noise, and to evaluate the mid-term results and survivorship. Patients and Methods. Between March 2009 and March 2011, 274 patients (310 hips) underwent cementless THA using a delta ceramic femoral head and liner. At each follow-up, clinical and radiological outcomes were recorded. A Kaplan-Meier analysis was undertaken to estimate survival. Results. Four patients (four hips) died and 18 patients (20 hips) were lost to follow-up within five years. The remaining 252 patients (286 hips) were followed for a mean of 66.5 months (60 to 84). There were 144 men (166 hips) and 108 women (120 hips) with a mean age of 49.7 years (16 to 83) at surgery. The mean pre-operative Harris Hip Score of 47.1 points improved to 93.8 points at final follow-up. Six patients reported squeaking in seven hips; however, none were audible. Radiolucent lines involving Gruen zones one and/or seven were seen in 52 hips (18.2%). No hip had detectable wear, focal osteolysis or signs of loosening. One hip was revised because of fracture of the ceramic liner, which occurred due to an undetected malseating of the ceramic liner at the time of surgery. One hip was revised for a periprosthetic fracture of the femur, and one hip was treated for periprosthetic joint infection. The six-year survivorship with re-operation for any reason as the endpoint was 99.0% (95% confidence interval 97.8% to 100%). Discussion. The rate of delta ceramic fracture was 0.3% (one of 286). While ceramic head fracture was dominant in previous ceramic-on-ceramic THA, fracture of the delta ceramic liner due to malseating is a concern. Cite this article: Bone Joint J 2017;99-B:741–8

Aims

To determine ten-year failure rates following 36 mm metal-on-metal (MoM) Pinnacle total hip arthroplasty (THA), and identify predictors of failure.

Aims

We performed a systematic review of the current literature regarding the outcomes of unconstrained metacarpophalangeal joint (MCPJ) arthroplasty.

Aims

We evaluated the short-term functional outcome and prevalence of bearing-specific generation of audible noise in 301 patients (336 hips) operated on with fourth generation (Delta) medium diameter head, ceramic-on-ceramic (CoC) total hip arthroplasties (THAs).

Objectives. Studies reporting specifically on squeaking in total hip arthroplasty have focused on cementless, and not on hybrid, fixation. We hypothesised that the cement mantle of the femur might have a damping effect on the sound transmitted through the metal stem. The objective of this study was to test the effect of cement on sound propagation along different stem designs and under different fixation conditions. Methods. An in vitro model for sound detection, composed of a mechanical suspension structure and a sound-registering electronic assembly, was designed. A pulse of sound in the audible range was propagated along bare stems and stems implanted in cadaveric bone femurs with and without cement. Two stems of different alloy and geometry were compared. Results. The magnitudes of the maximum amplitudes of the bare stem were in the range of 10.8 V to 11.8 V, whereas the amplitudes for the same stems with a cement mantle in a cadaveric bone decreased to 0.3 V to 0.7 V, implying a pulse-attenuation efficiency of greater than 97%. The same magnitude is close to 40% when the comparison is made against stems implanted in cadaveric bone femurs without cement. Conclusion. The in vitro model presented here has shown that the cement had a remarkable effect on sound attenuation and a strong energy absorption in cement mantle and bone. The visco-elastic properties of cement can contribute to the dissipation of vibro-acoustic energy, thus preventing hip prostheses from squeaking. This could explain, at least in part, the lack of reports of squeaking when hybrid fixation is used. Cite this article: F. J. Burgo, D. E. Mengelle, A. Ozols, C. Fernandez, C. M. Autorino. The damping effect of cement as a potential mitigation factor of squeaking in ceramic-on-ceramic total hip arthroplasty. Bone Joint Res 2016;5:531–537. DOI: 10.1302/2046-3758.511.BJR-2016-0058.R1

Aims. Long-term clinical outcomes for ceramic-on-ceramic (CoC) bearings are encouraging. However, there is a risk of squeaking. Guidelines for the orientation of the acetabular component are defined from static imaging, but the position of the pelvis and thus the acetabular component during activities associated with edge-loading are likely to be very different from those measured when the patient is supine. We assessed the functional orientation of the acetabular component. Patients and Methods. A total of 18 patients with reproducible squeaking in their CoC hips during deep flexion were investigated with a control group of 36 non-squeaking CoC hips. The two groups were matched for the type of implant, the orientation of the acetabular component when supine, the size of the femoral head, ligament laxity, maximum hip flexion and body mass index. . Results. The mean functional anteversion of the acetabular component at the point when patients initiated rising from a seated position was significantly less in the squeaking group than in the control group, 8.1° (-10.5° to 36.0°) and 21.1° (-1.9° to 38.4°) respectively (p = 0.002). . Conclusion. The functional orientation of the acetabular component during activities associated with posterior edge-loading are different from those measured when supine due to patient-specific pelvic kinematics. Individuals with a large anterior pelvic tilt during deep flexion might be more susceptible to posterior edge-loading and squeaking as a consequence of a significant decrease in the functional anteversion of the acetabular component. . Cite this article: Bone Joint J 2016;98-B:910–16

The leading indication for revision total hip arthroplasty (THA) remains aseptic loosening owing to wear. The younger, more active patients currently undergoing THA present unprecedented demands on the bearings. Ceramic-on-ceramic (CoC) bearings have consistently shown the lowest rates of wear. The recent advances, especially involving alumina/zirconia composite ceramic, have led to substantial improvements and good results in vitro.

Alumina/zirconia composite ceramics are extremely hard, scratch resistant and biocompatible. They offer a low co-efficient of friction and superior lubrication and lower rates of wear compared with other bearings. The major disadvantage is the risk of fracture of the ceramic. The new composite ceramic has reduced the risk of fracture of the femoral head to 0.002%. The risk of fracture of the liner is slightly higher (0.02%).

Assuming that the components are introduced without impingement, CoC bearings have major advantages over other bearings. Owing to the superior hardness, they produce less third body wear and are less vulnerable to intra-operative damage.

The improved tribology means that CoC bearings are an excellent choice for young, active patients requiring THA.

Cite this article: Bone Joint J 2016;98-B(1 Suppl A):14–17.

As adverse events related to metal on metal hip arthroplasty have been better understood, there has been increased interest in toxicity related to the high circulating levels of cobalt ions. However, distinguishing true toxicity from benign elevations in cobalt levels can be challenging. The purpose of this review is to examine the use of cobalt alloys in total hip arthroplasty, to review the methods of measuring circulating cobalt levels, to define a level of cobalt which is considered pathological and to review the pathophysiology, risk factors and treatment of cobalt toxicity. To the best of our knowledge, there are 18 published cases where cobalt metal ion toxicity has been attributed to the use of cobalt-chromium alloys in hip arthroplasty. Of these cases, the great majority reported systemic toxic reactions at serum cobalt levels more than 100 μg/L. This review highlights some of the clinical features of cobalt toxicity, with the goal that early awareness may decrease the risk factors for the development of cobalt toxicity and/or reduce its severity.

Take home message: Severe adverse events can arise from the release of cobalt from metal-on-metal arthroplasties, and as such, orthopaedic surgeons should not only be aware of the presenting problems, but also have the knowledge to treat appropriately.

Cite this article: Bone Joint J 2016;98-B:14–20.

Ideal placement of the acetabular component remains elusive both in terms of defining and achieving a target. Our aim is to help restore original anatomy by using the transverse acetabular ligament (TAL) to control the height, depth and version of the component. In the normal hip the TAL and labrum extend beyond the equator of the femoral head and therefore, if the definitive acetabular component is positioned such that it is cradled by and just deep to the plane of the TAL and labrum and is no more than 4mm larger than the original femoral head, the centre of the hip should be restored. If the face of the component is positioned parallel to the TAL and psoas groove the patient specific version should be restored. We still use the TAL for controlling version in the dysplastic hip because we believe that the TAL and labrum compensate for any underlying bony abnormality.

The TAL should not be used as an aid to inclination. Worldwide, > 75% of surgeons operate with the patient in the lateral decubitus position and we have shown that errors in post-operative radiographic inclination (RI) of > 50° are generally caused by errors in patient positioning. Consequently, great care needs to be taken when positioning the patient. We also recommend 35° of apparent operative inclination (AOI) during surgery, as opposed to the traditional 45°.

Cite this article: Bone Joint J 2016;98-B(1 Suppl A):37–43.

A number of studies have reported satisfactory results from the isolated revision of an acetabular component. However, many of these studies reported only the short- to intermediate-term results of heterogeneous bearing surfaces in a mixed age group.

We present our experience of using a ceramic-on-ceramic (CoC) bearing for isolated revision of an uncemented acetabular component in 166 patients (187 hips) who were under the age of 50 years at the time of revision. There were 78 men and 88 women with a mean age of 47.4 years (28 to 49). The most common reason for revision was polyethylene wear and acetabular osteolysis in 123 hips (66%), followed by aseptic loosening in 49 hips (26%).

We report the clinical and radiological outcome, complication rate, and survivorship of this group. The mean duration of follow-up was 15.6 years (11 to 19).

The mean pre-operative Harris hip score was 33 points (1 to 58), and improved to a mean of 88 points (51 to 100) at follow-up. The mean pre-operative total Western Ontario and McMaster Universities Osteoarthritis Index score was 63.2 (43 to 91) and improved to 19.8 points (9 to 61) post-operatively. Overall, 153 of 166 patients (92%) were satisfied with their outcome. Kaplan–Meier survivorship analysis, with revision or radiological evidence of implant failure (13 patients, 8%) as end-points, was 92% at 15 years (95% confidence interval 0.89 to 0.97).

Isolated revision of a cementless acetabular component using a CoC bearing gives good results in patients under 50 years of age.

Cite this article: Bone Joint J 2015;97-B:1197–1203.

Oxidised zirconium (OxZi) has been developed as an alternative bearing surface for femoral heads in total hip arthroplasty (THA). This study has investigated polyethylene wear, functional outcomes and complications, comparing OxZi and cobalt–chrome (CoCr) as part of a three-arm, multicentre randomised controlled trial. Patients undergoing THA from four institutions were prospectively randomised into three groups. Group A received a CoCr femoral head and highly cross-linked polyethylene (XLPE) liner; Group B received an OxZi femoral head and XLPE liner; Group C received an OxZi femoral head and ultra-high molecular weight polyethylene (UHMWPE) liner. At five years, 368 patients had no statistically significant differences in short-form-36 (p = 0.176 mental, p = 0.756 physical), Western Ontario and McMaster Universities Osteoarthritis Index (p = 0.847), pain scores (p = 0.458) or complications. The mean rate of linear wear was 0.028 mm/year (standard deviation (sd) 0.010) for Group A, 0.023 mm/year (sd 0.010) for Group B, and 0.09 mm/year (sd 0.045) for Group C. Penetration was significantly higher in the UHMWPE liner group compared with both XLPE liner groups (p < 0.001) but no significant difference was noted between CoCr and OxZi when articulating with XLPE (p = 0.153). In this, the largest randomised study of this bearing surface, it appears that using a XLPE acetabular liner is more important in reducing THA component wear than the choice of femoral head bearing, at mid-term follow-up. There is a non-significant trend towards lower wear, coupling OxZi rather than CoCr with XLPE but long-term analysis is required to see if this observation changes with time and becomes significant.

Cite this article: Bone Joint J 2015;97-B:883–9.

A high radiographic inclination angle (RI) contributes to accelerated wear and has been associated with dislocation after total hip arthroplasty (THA). With freehand positioning of the acetabular component there is a lack of accuracy, with a trend towards a high radiographic inclination angle. The aim of this study was to investigate whether the use of a digital protractor to measure the operative inclination angle (OI) could improve the positioning of the acetabular component in relation to a ‘safe zone’.

We measured the radiographic inclination angles of 200 consecutive uncemented primary THAs. In the first 100 the component was introduced freehand and in the second 100 a digital protractor was used to measure the operative inclination angle.

The mean difference between the operative and the radiographic inclination angles (∆RI–OI) in the second cohort was 12.3° (3.8° to 19.8°). There was a strong correlation between the circumference of the hip and ∆RI–OI. The number of RI outliers was significantly reduced in the protractor group (p = 0.002).

Adjusting the OI, using a digital protractor and taking into account the circumference of the patient’s hip, improves the RI significantly (p < 0.001) and does not require additional operating time.

Cite this article: Bone Joint J 2015; 97-B:603–610.

In this in vitro study of the hip joint we examined which soft tissues act as primary and secondary passive rotational restraints when the hip joint is functionally loaded. A total of nine cadaveric left hips were mounted in a testing rig that allowed the application of forces, torques and rotations in all six degrees of freedom. The hip was rotated throughout a complete range of movement (ROM) and the contributions of the iliofemoral (medial and lateral arms), pubofemoral and ischiofemoral ligaments and the ligamentum teres to rotational restraint was determined by resecting a ligament and measuring the reduced torque required to achieve the same angular position as before resection. The contribution from the acetabular labrum was also measured. Each of the capsular ligaments acted as the primary hip rotation restraint somewhere within the complete ROM, and the ligamentum teres acted as a secondary restraint in high flexion, adduction and external rotation. The iliofemoral lateral arm and the ischiofemoral ligaments were primary restraints in two-thirds of the positions tested. Appreciation of the importance of these structures in preventing excessive hip rotation and subsequent impingement/instability may be relevant for surgeons undertaking both hip joint preserving surgery and hip arthroplasty.

Cite this article: Bone Joint J 2015; 97-B:484–91.

Ceramic-on-metal (CoM) is a relatively new bearing combination for total hip arthroplasty (THA) with few reported outcomes. A total of 287 CoM THAs were carried out in 271 patients (mean age 55.6 years (20 to 77), 150 THAs in female patients, 137 in male) under the care of a single surgeon between October 2007 and October 2009. With the issues surrounding metal-on-metal bearings the decision was taken to review these patients between March and November 2011, at a mean follow-up of 34 months (23 to 45) and to record pain, outcome scores, radiological analysis and blood ion levels. The mean Oxford Hip Score was 19.2 (12 to 53), 254 patients with 268 hips (95%) had mild/very mild/no pain, the mean angle of inclination of the acetabular component was 44.8^o (28^o to 63^o), 82 stems (29%) had evidence of radiolucent lines of > 1 mm in at least one Gruen zone and the median levels of cobalt and chromium ions in the blood were 0.83 μg/L (0.24 μg/L to 27.56 μg/L) and 0.78 μg/L (0.21 μg/L to 8.84 μg/L), respectively. The five-year survival rate is 96.9% (95% confidence interval 94.7% to 99%).

Due to the presence of radiolucent lines and the higher than expected levels of metal ions in the blood, we would not recommend the use of CoM THA without further long-term follow-up. We plan to monitor all these patients regularly.

Cite this article: Bone Joint J 2015;97-B:300–5.

This review examines the future of total hip arthroplasty, aiming to avoid past mistakes

We conducted a retrospective study to assess the prevalence of adverse reactions to metal debris (ARMD) in patients operated on at our institution with metal-on-metal (MoM) total hip replacements with 36 mm heads using a Pinnacle acetabular shell. A total of 326 patients (150 males, 175 hips; 176 females, 203 hips) with a mean age of 62.7 years (28 to 85) and mean follow-up of 7.5 years (0.1 to 10.8) participating in our in-depth modern MoM follow-up programme were included in the study, which involved recording whole blood cobalt and chromium ion measurements, Oxford hip scores (OHS) and plain radiographs of the hip and targeted cross-sectional imaging. Elevated blood metal ion levels (> 5 parts per billion) were seen in 32 (16.1%) of the 199 patients who underwent unilateral replacement. At 23 months after the start of our modern MoM follow-up programme, 29 new cases of ARMD had been revealed. Hence, the nine-year survival of this cohort declined from 96% (95% CI 95 to 98) with the old surveillance routine to 86% (95% CI 82 to 90) following the new protocol. Although ARMD may not be as common in 36 mm MoM THRs as in those with larger heads, these results support the Medicines and Healthcare Products Regulatory Agency guidelines on regular reviews and further investigations, and emphasise the need for specific a follow-up programme for patients with MoM THRs.

Cite this article: Bone Joint J 2014; 96-B:1610–17.

Large femoral heads have become popular in total hip replacement (THR) as a method of reducing the risk of dislocation. However, if large heads are used in ceramic-on-ceramic THR, the liner must be thinner, which may increase the risk of fracture. To compare the rates of ceramic fracture and dislocation between 28 mm and 32 mm ceramic heads, 120 hips in 109 patients (51 men and 58 women, mean age 49.2 years) were randomised to THR with either a 28 mm or a 32 mm ceramic articulation. A total of 57/60 hips assigned to the 28 mm group and 55/60 hips assigned to the 32 mm group were followed for at least five years. No ceramic component fractures occured in any patient in either group. There was one dislocation in the 32 mm group and none in the 28 mm group (p = 0.464). No hip had detectable wear, focal osteolysis or prosthetic loosening. In our small study the 32 mm ceramic articulation appeared to be safe in terms of ceramic liner fracture.

Cite this article: Bone Joint J 2014;96-B:1459–63.

The June 2014 Hip & Pelvis Roundup³⁶⁰ looks at: Modular femoral necks: early signs are not good; is corrosion to blame for modular neck failures; metal-on-metal is not quite a closed book; no excess failures in fixation of displaced femoral neck fractures; noise no problem in hip replacement; heterotopic ossification after hip arthroscopy: are NSAIDs the answer?; thrombotic and bleeding events surprisingly low in total joint replacement; and the elephant in the room: complications and surgical volume.

Objectives

Our study aimed to examine not only the incidence but also the impact of noise from two types of total hip replacement articulations: ceramic-on-ceramic and ceramic-on-polyethylene.

The April 2014 Hip & Pelvis Roundup. 360 . looks at: Recent arthroplasty and flight; whether that squeak could be a fracture; diagnosing early infected hip replacement; impaction grafting at a decade; whether squeaking is more common than previously thought; femoral offset associated with post THR outcomes; and periprosthetic fracture stabilisation

Objectives

Wear debris released from bearing surfaces has been shown to provoke negative immune responses in the recipient. Excessive wear has been linked to early failure of prostheses. Analysis using coordinate measuring machines (CMMs) can provide estimates of total volumetric material loss of explanted prostheses and can help to understand device failure. The accuracy of volumetric testing has been debated, with some investigators stating that only protocols involving hundreds of thousands of measurement points are sufficient. We looked to examine this assumption and to apply the findings to the clinical arena.

The February 2014 Hip & Pelvis Roundup³⁶⁰ looks at: length of stay; cementless metaphyseal fixation; mortality trends in over 400,000 total hip replacements; antibiotics in hip fracture surgery; blood supply to the femoral head after dislocation; resurfacing and THR in metal-on-metal replacement; diabetes and hip replacement; bone remodelling over two decades following hip replacement; and whether bisphosphonates affect acetabular fixation.

We reviewed the literature on the currently available choices of bearing surface in total hip replacement (THR). We present a detailed description of the properties of articulating surfaces review the understanding of the advantages and disadvantages of existing bearing couples. Recent technological developments in the field of polyethylene and ceramics have altered the risk of fracture and the rate of wear, although the use of metal-on-metal bearings has largely fallen out of favour, owing to concerns about reactions to metal debris. As expected, all bearing surface combinations have advantages and disadvantages. A patient-based approach is recommended, balancing the risks of different options against an individual’s functional demands.

Cite this article: Bone Joint J 2014;96-B:147–56.

Squeaking arising from a ceramic-on-ceramic (CoC) total hip replacement (THR) may cause patient concern and in some cases causes patients to seek revision surgery. We performed a meta-analysis to determine the incidence of squeaking and the incidence of revision surgery for squeaking. A total of 43 studies including 16 828 CoC THR that reported squeaking, or revision for squeaking, were entered into the analysis. The incidence of squeaking was 4.2% and the incidence of revision for squeaking was 0.2%. The incidence of squeaking in patients receiving the Accolade femoral stem was 8.3%, and the incidence of revision for squeaking in these patients was 1.3%. Cite this article: Bone Joint J 2014;96-B:181–7

We report the clinical and radiological outcomes of a series of contemporary cementless ceramic-on-ceramic total hip replacements (THRs) at ten years in patients aged ≤ 55 years of age. Pre- and post-operative activity levels are described. A total of 120 consecutive ceramic cementless THRs were performed at a single centre in 110 patients from 1997 to 1999. The mean age of the patients at operation was 45 years (20 to 55). At ten years, four patients had died and six were lost to follow-up, comprising ten hips. The mean post-operative Harris hip score was 94.7 (55 to 100). Radiological analysis was undertaken in 90 available THRs of the surviving 106 hips at final review: all had evidence of stable bony ingrowth, with no cases of osteolysis. Wear was undetectable. There were four revisions. The survival for both components with revision for any cause as an endpoint was 96.5% (95% confidence interval 94.5 to 98.7). The mean modified University of California, Los Angeles activity level rose from a mean of 6.4 (4 to 10) pre-operatively to 9.0 (6 to 10) at the ten-year post-operative period.

Alumina ceramic-on-ceramic bearings in cementless primary THR in this series have resulted in good clinical and radiological outcomes with undetectable rates of wear and excellent function in the demanding younger patient group at ten years.

Cite this article: Bone Joint J 2013;95-B:1603–9.

A total of 219 hips in 192 patients aged between 18 and 65 years were randomised to 28-mm metal-on-metal uncemented total hip replacements (THRs, 107 hips) or hybrid hip resurfacing (HR, 112 hips). At a mean follow-up of eight years (6.6 to 9.3) there was no significant difference between the THR and HR groups regarding rate of revision (4.0% (4 of 99) vs 5.8% (6 of 104), p = 0.569) or re-operation rates without revision (5.1% (5 of 99) vs 2.9% (3 of 104), p = 0.428). In the THR group one recurrent dislocation, two late deep infections and one peri-prosthetic fracture required revision, whereas in the HR group five patients underwent revision for femoral head loosening and one for adverse reaction to metal debris. The mean University of California, Los Angeles activity scores were significantly higher in HR (7.5 (sd 1.7) vs 6.9 (sd 1.7), p = 0.035), but similar mean Western Ontario and McMaster Universities Osteoarthritis Index scores were obtained (5.8 (sd 9.5) in HR vs 5.1 (sd 8.9) in THR, p = 0.615) at the last follow-up. Osteolysis was found in 30 of 81 THR patients (37.4%), mostly in the proximal femur, compared with two of 83 HR patients (2.4%) (p < 0.001). At five years the mean metal ion levels were < 2.5 μg/l for cobalt and chromium in both groups; only titanium was significantly higher in the HR group (p = 0.001). Although revision rates and functional scores were similar in both groups at mid-term, long-term survival analysis is necessary to determine whether one procedure is more advantageous than the other.

Cite this article: Bone Joint J 2013;95-B:1464–73.

The October 2013 Hip & Pelvis Roundup³⁶⁰ looks at: Young and impinging; Clothes, weather and femoral heads?; Go long, go cemented; Surgical repair of the abductors?; Aspirin for DVT prophylaxis?; Ceramic-on-polyethylene: a low-wear solution?; ALVAL and ASR™: the story continues….; Salvaging Legg-Calve-Perthes’ disease

Orientation of the acetabular component influences wear, range of movement and the incidence of dislocation after total hip replacement (THR). During surgery, such orientation is often referenced to the anterior pelvic plane (APP), but APP inclination relative to the coronal plane (pelvic tilt) varies substantially between individuals. In contrast, the change in pelvic tilt from supine to standing (dPT) is small for nearly all individuals. Therefore, in THR performed with the patient supine and the patient’s coronal plane parallel to the operating table, we propose that freehand placement of the acetabular component placement is reliable and reflects standing (functional) cup position. We examined this hypothesis in 56 hips in 56 patients (19 men) with a mean age of 61 years (29 to 80) using three-dimensional CT pelvic reconstructions and standing lateral pelvic radiographs. We found a low variability of acetabular component placement, with 46 implants (82%) placed within a combined range of 30° to 50° inclination and 5° to 25° anteversion. Changing from the supine to the standing position (analysed in 47 patients) was associated with an anteversion change < 10° in 45 patients (96%). dPT was < 10° in 41 patients (87%). In conclusion, supine THR appears to provide reliable freehand acetabular component placement. In most patients a small reclination of the pelvis going from supine to standing causes a small increase in anteversion of the acetabular component.

Cite this article: Bone Joint J 2013;95-B:1326–31.

The April 2013 Hip & Pelvis Roundup³⁶⁰ looks at: hip cartilage and magnets; labral repair or resection; who benefits from injection; rotational osteotomy for osteonecrosis; whether ceramic implants risk fracture; dual articulation; and hydroxyapatite.

The practice of removing a well-fixed cementless femoral component is associated with high morbidity. Ceramic bearing couples are low wearing and their use minimises the risk of subsequent further revision due to the production of wear debris. A total of 165 revision hip replacements were performed, in which a polyethylene-lined acetabular component was revised to a new acetabular component with a ceramic liner, while retaining the well-fixed femoral component. A titanium sleeve was placed over the used femoral trunnion, to which a ceramic head was added. There were 100 alumina and 65 Delta bearing couples inserted.

The mean Harris hip score improved significantly from 71.3 (9.0 to 100.0) pre-operatively to 91.0 (41.0 to 100.0) at a mean follow up of 4.8 years (2.1 to 12.5) (p < 0.001). No patients reported squeaking of the hip.

There were two fractures of the ceramic head, both in alumina bearings. No liners were seen to fracture. No fractures were observed in components made of Delta ceramic. At 8.3 years post-operatively the survival with any cause of failure as the endpoint was 96.6% (95% confidence interval (CI) 85.7 to 99.3) for the acetabular component and 94.0% (95% CI 82.1 to 98.4) for the femoral component.

The technique of revising the acetabular component in the presence of a well-fixed femoral component with a ceramic head placed on a titanium sleeve over the used trunnion is a useful adjunct in revision hip practice. The use of Delta ceramic is recommended.

Cite this article: Bone Joint J 2013;95-B:333–8.

Noise generation has been reported with ceramic-on-ceramic articulations in total hip replacement (THR). This study evaluated 208 consecutive Delta Motion THRs at a mean follow-up of 21 months (12 to 35). There were 141 women and 67 men with a mean age of 59 years (22 to 84). Patients were reviewed clinically and radiologically, and the incidence of noise was determined using a newly described assessment method. Noise production was examined against range of movement, ligamentous laxity, patient-reported outcome scores, activity level and orientation of the acetabular component. There were 143 silent hips (69%), 22 (11%) with noises other than squeaking, 17 (8%) with unreproducible squeaking and 26 (13%) with reproducible squeaking. Hips with reproducible squeaking had a greater mean range of movement (p < 0.001) and mean ligament laxity (p = 0.004), smaller median head size (p = 0.01) and decreased mean acetabular component inclination (p = 0.02) and anteversion angle (p = 0.02) compared with the other groups. There was no relationship between squeaking and age (p = 0.13), height (p = 0.263), weight (p = 0.333), body mass index (p = 0.643), gender (p = 0.07) or patient outcome score (p = 0.422). There were no revisions during follow-up. Despite the surprisingly high incidence of squeaking, all patients remain satisfied with their hip replacement. Cite this article: Bone Joint J 2013;95-B:160–5