Aims

We compared the outcome of total hip arthroplasty (THA) in obese patients who previously underwent bariatric surgery and those who did not, in a matched cohort study.

Aim

Until now, there has been no consensus as to whether stemmed acetabular components are appropriate for use in patients undergoing revision total hip arthroplasty (THA) who have major acetabular defects or pelvic discontinuity. We wished to address this deficiency in the literature.

Aims

The optimal management of intracapsular fractures of the femoral neck in independently mobile patients remains open to debate. Successful fixation obviates the limitations of arthroplasty for this group of patients. However, with fixation failure rates as high as 30%, the outcome of revision surgery to salvage total hip arthroplasty (THA) must be considered. We carried out a systematic review to compare the outcomes of salvage THA and primary THA for intracapsular fractures of the femoral neck.

Aims

We present a case series of ten metal-on-polyethylene total hip arthroplasties (MoP THAs) with delayed dislocation associated with unrecognised adverse local tissue reaction due to corrosion at the trunnion and pseudotumour formation.

Objectives

T-cells are considered to play an important role in the inflammatory response causing arthroplasty failure. The study objectives were to investigate the composition and distribution of CD4+ T-cell phenotypes in the peripheral blood (PB) and synovial fluid (SF) of patients undergoing revision surgery for failed metal-on-metal (MoM) and metal-on-polyethylene (MoP) hip arthroplasties, and in patients awaiting total hip arthroplasty.

Given the increasing number of total hip arthroplasty procedures being performed annually, it is imperative that orthopaedic surgeons understand factors responsible for instability. In order to treat this potentially complex problem, we recommend correctly classifying the type of instability present based on component position, abductor function, impingement, and polyethylene wear. Correct classification allows the treating surgeon to choose the appropriate revision option that ultimately will allow for the best potential outcome.

Cite this article: Bone Joint J 2016;98-B(1 Suppl A):44–9.

Revision of a cemented hemiarthroplasty of the hip may be a hazardous procedure with high rates of intra-operative complications. Removing well-fixed cement is time consuming and risks damaging already weak bone or perforating the femoral shaft. The cement-in-cement method avoids removal of intact cement and has shown good results when used for revision total hip arthroplasty (THA). The use of this technique for the revision of a hemiarthroplasty to THA has not been previously reported. A total of 28 consecutive hemiarthroplasties (in 28 patients) were revised to a THA using an Exeter stem and the cement-in-cement technique. There were four men and 24 women; their mean age was 80 years (35 to 93). Clinical and radiographic data, as well as operative notes, were collected prospectively and no patient was lost to follow-up. Four patients died within two years of surgery. The mean follow up of the remainder was 70 months (25 to 124). Intra-operatively there was one proximal perforation, one crack of the femoral calcar and one acetabular fracture. No femoral components have required subsequent revision for aseptic loosening or are radiologically loose. . Four patients with late complications (14%) have since undergone surgery (two for a peri-prosthetic fracture, and one each for deep infection and recurrent dislocation) resulting in an overall major rate of complication of 35.7%. The cement-in-cement technique provides reliable femoral fixation in this elderly population and may reduce operating time and rates of complication. Cite this article: Bone Joint J 2015;97-B:1623–7

The early failure and revision of bimodular primary total hip arthroplasty prostheses requires the identification of the risk factors for material loss and wear at the taper junctions through taper wear analysis. Deviations in taper geometries between revised and pristine modular neck tapers were determined using high resolution tactile measurements. A new algorithm was developed and validated to allow the quantitative analysis of material loss, complementing the standard visual inspection currently used.

The algorithm was applied to a sample of 27 retrievals (in situ from 2.9 to 38.1 months) of the withdrawn Rejuvenate modular prosthesis. The mean wear volumes on the flat distal neck piece taper was 3.35 mm³ (0.55 to 7.57), mainly occurring in a characteristic pattern in areas with high mechanical loading. Wear volume tended to increase with time to revision (r² = 0.423, p = 0.001). Implant and patient specific data (offset, stem size, patient’s mass, age and body mass index) did not correlate with the amount of material loss observed (p >  0.078). Bilaterally revised implants showed higher amounts of combined total material loss and similar wear patterns on both sides. The consistent wear pattern found in this study has not been reported previously, suggesting that the device design and materials are associated with the failure of this prosthesis.

Cite this article: Bone Joint J 2015;97-B:1350–7.

Patients from a randomised trial on resurfacing hip arthroplasty (RHA) (n = 36, 19 males; median age 57 years, 24 to 65) comparing a conventional 28 mm metal-on-metal total hip arthroplasty (MoM THA) (n = 28, 17 males; median age 59 years, 37 to 65) and a matched control group of asymptomatic patients with a 32 mm ceramic-on-polyethylene (CoP) THA (n = 33, 18 males; median age 63 years, 38 to 71) were cross-sectionally screened with metal artefact reducing sequence-MRI (MARS-MRI) for pseudotumour formation at a median of 55 months (23 to 72) post-operatively. MRIs were scored by consensus according to three different classification systems for pseudotumour formation.

Clinical scores were available for all patients and metal ion levels for MoM bearing patients.

Periprosthetic lesions with a median volume of 16 mL (1.5 to 35.9) were diagnosed in six patients in the RHA group (17%), one in the MoM THA group (4%) and six in the CoP group (18%). The classification systems revealed no clear differences between the groups. Solid lesions (n = 3) were exclusively encountered in the RHA group. Two patients in the RHA group and one in the MoM THA group underwent a revision for pseudotumour formation. There was no statistically significant relationship between clinical scoring, metal ion levels and periprosthetic lesions in any of the groups.

Periprosthetic fluid collections are seen on MARS-MRI after conventional CoP THA and RHA and may reflect a soft-tissue collection or effusion.

Currently available MRI classification systems seem to score these collections as pseudotumours, causing an-overestimatation of the incidence of pseudotumours.

Cite this article: Bone Joint J 2015;97-B:1175–82.

The long term biological effects of wear products following total hip arthroplasty (THA) are unclear. However, the indications for THA are expanding, with increasingly younger patients undergoing the procedure.

This prospective, randomised study compared two groups of patients undergoing THA after being randomised to receive one of two different bearing surfaces: metal-on-polyethylene (MoP) n = 22 and metal-on-metal (MoM) n = 23. We investigated the relationship between three variables: bearing surface (MoP vs MoM), whole blood levels of chromium (Cr) and cobalt (Co) and chromosomal aberrations in peripheral lymphocyte pre-operatively and at one, two and five years post-surgery.

Our results demonstrated significantly higher mean cobalt and chromium (Co and Cr) blood levels in the MoM group at all follow-up points following surgery (p < 0.01), but there were no significant differences in the chromosomal aberration indices between MoM and MoP at two or five years (two years: p = 0.56, p = 0.08, p = 0.91, p = 0.51 and five years: p = 0.086, p = 0.73, p = 0.06, p = 0.34) for translocations, breaks, loss and gain of chromosomes respectively. Regression analysis showed a strong linear relationship between Cr levels and the total chromosomal aberration indices in the MoM group (R² = 0.90016), but this was not as strong for Co (R² = 0.68991). In the MoP group, the analysis revealed a poor relationship between Cr levels and the total chromosomal aberration indices (R² = 0.23908) but a slightly stronger relationship for Co (R² = 0.64292). Across both groups, Spearman’s correlation detected no overall association between Co and Cr levels and each of the studied chromosomal aberrations. There remains no clear indication which THA bearing couple is the most biocompatible, especially in young active patients. While THA continues to be very successful at alleviating pain and restoring function, the long-term biological implications of the procedure still require further scrutiny.

Cite this article: Bone Joint J 2015;97-B:1183–91.

The outcome of 219 revision total hip arthroplasties (THAs) in 98 male and 121 female patients, using 137 long length and 82 standard length cemented collarless double-taper femoral stems in 211 patients, with a mean age of 72 years (30 to 90) and mean follow-up of six years (two to 18) have been described previously. We have extended the follow-up to a mean of 13 years (8 to 20) in this cohort of patients in which the pre-operative bone deficiency Paprosky grading was IIIA or worse in 79% and 73% of femurs with long and standard stems, respectively.

For the long stem revision group, survival to re-revision for aseptic loosening at 14 years was 97% (95% confidence interval (CI) 91 to 100) and in patients aged > 70 years, survival was 100%. Two patients (two revisions) were lost to follow-up and 86 patients with 88 revisions had died. Worst-case analysis for survival to re-revision for aseptic loosening at 14 years was 95% (95% CI 89 to 100) and 99% (95% CI 96 to 100) for patients aged > 70 years. One additional long stem was classified as loose radiographically but not revised.

For the standard stem revision group, survival to re-revision for aseptic loosening at 14 years was 91% (95% CI 83 to 99). No patients were lost to follow-up and 49 patients with 51 hips had died. No additional stems were classified as loose radiographically.

Femoral revision using a cemented collarless double-taper stem, particularly with a long length stem, and in patients aged > 70 years, continues to yield excellent results up to 20 years post-operatively, including in hips with considerable femoral metaphyseal bone loss.

Cite this article: Bone Joint J 2015;97-B:1038–45.

Tranexamic acid (TXA), an inhibitor of fibrinolysis, reduces blood loss after total knee arthroplasty. However, its effect on minimally invasive total hip arthroplasty (THA) is not clear. We performed a prospective, randomised double-blind study to evaluate the effect of two intravenous injections of TXA on blood loss in patients undergoing minimally invasive THA.

In total, 60 patients (35 women and 25 men with a mean age of 58.1 years; 17 to 84) who underwent unilateral minimally invasive uncemented THA were randomly divided into the study group (30 patients, 20 women and ten men with a mean age of 56.5 years; 17 to 79) that received two intravenous injections 1 g of TXA pre- and post-operatively (TXA group), and a placebo group (30 patients, 15 women and 15 men with a mean age of 59.5 years; 23 to 84). We compared the peri-operative blood loss of the two groups. Actual blood loss was calculated from the maximum reduction in the level of haemoglobin. All patients were followed clinically for the presence of venous thromboembolism.

The TXA group had a lower mean intra-operative blood loss of 441 ml (150 to 800) versus 615 ml (50 to 1580) in the placebo (p = 0.044), lower mean post-operative blood loss (285 ml (120 to 570) versus 392 ml (126 to 660) (p = 0.002), lower mean total blood loss (1070 ml (688 to 1478) versus 1337 ml (495 to 2238) (p = 0.004) and lower requirement for transfusion (p = 0.021). No patients in either group had symptoms of venous thromboembolism or wound complications.

This prospective, randomised controlled study showed that a regimen of two intravenous injections of 1 g TXA is effective for blood conservation after minimally invasive THA.

Cite this article: Bone Joint J 2015;97-B:905–10.

Tribocorrosion at the head–neck taper interface – so-called ‘taperosis’ – may be a source of metal ions and particulate debris in metal-on-polyethylene total hip arthroplasty (THA).

We examined the effect of femoral head length on fretting and corrosion in retrieved head–neck tapers in vivo for a minimum of two years (mean 8.7 years; 2.6 to 15.9). A total of 56 femoral heads ranging from 28 mm to 3 mm to 28 mm + 8 mm, and 17 femoral stems featuring a single taper design were included in the study. Fretting and corrosion were scored in three horizontally oriented concentric zones of each taper by stereomicroscopy.

Head length was observed to affect fretting (p = 0.03), with 28 mm + 8 mm femoral heads showing greater total fretting scores than all other head lengths. The central zone of the femoral head bore taper was subject to increased fretting damage (p = 0.01), regardless of head length or stem offset. High-offset femoral stems were associated with greater total fretting of the bore taper (p = 0.04).

Increased fretting damage is seen with longer head lengths and high-offset femoral stems, and occurs within a central concentric zone of the femoral head bore taper. Further investigation is required to determine the effect of increased head size, and variations in head–neck taper design.

Cite this article: Bone Joint J 2015; 97-B:911–16.

The peri-prosthetic tissue response to wear debris is complex and influenced by various factors including the size, area and number of particles. We hypothesised that the ‘biologically active area’ of all metal wear particles may predict the type of peri-prosthetic tissue response. . Peri-prosthetic tissue was sampled from 21 patients undergoing revision of a small diameter metal-on-metal (MoM) total hip arthroplasty (THA) for aseptic loosening. An enzymatic protocol was used for tissue digestion and scanning electron microscope was used to characterise particles. Equivalent circle diameters and particle areas were calculated. Histomorphometric analyses were performed on all tissue specimens. Aspirates of synovial fluid were collected for analysis of the cytokine profile analysis, and compared with a control group of patients undergoing primary THA (n = 11) and revision of a failed ceramic-on-polyethylene arthroplasty (n = 6). . The overall distribution of the size and area of the particles in both lymphocyte and non-lymphocyte-dominated responses were similar; however, the subgroup with lymphocyte-dominated peri-prosthetic tissue responses had a significantly larger total number of particles. . 14 cytokines (interleukin (IL)-1ß, IL-2, IL-4, IL-5, IL-6, IL-10, IL-13, IL-17, interferon (IFN)-γ, and IFN-gamma-inducible protein 10), chemokines (macrophage inflammatory protein (MIP)-1α and MIP-1ß), and growth factors (granulocyte macrophage colony stimulating factor (GM-CSF) and platelet derived growth factor) were detected at significantly higher levels in patients with metal wear debris compared with the control group. . Significantly higher levels for IL-1ß, IL-5, IL-10 and GM-CSF were found in the subgroup of tissues from failed MoM THAs with a lymphocyte-dominated peri-prosthetic response compared with those without this response. . These results suggest that the ‘biologically active area’ predicts the type of peri-prosthetic tissue response. The cytokines IL-1ß, IL-5, IL-10, and GM-CSF are associated with lymphocyte-dominated tissue responses from failed small-diameter MoM THA. Cite this article: Bone Joint J 2015;97-B:917–23

This study reports the results of 38 total hip arthroplasties (THAs) in 33 patients aged <  50 years, using the JRI Furlong hydroxyapatite ceramic (HAC)-coated femoral component. This represents an update of previous reports of the same cohort at ten and 16 years, which were reported in 2004 and 2009, respectively. We describe the survival, radiological and functional outcomes at a mean follow-up of 21 years (17 to 25). Of the surviving 34 THAs, one underwent femoral revision for peri-prosthetic fracture after 21 years, and one patient (one hip) was lost to follow-up. Using aseptic loosening as the end-point, 12 hips (31.5%) needed acetabular revision but none needed femoral revision, demonstrating 100% survival (95% confidence interval 89 to 100). In young patients with high demands, the Furlong HAC–coated femoral component gives excellent long-term results. Cite this article: Bone Joint J 2015;97-B:749–54

We report the clinical and radiographic outcomes of 208 consecutive femoral revision arthroplasties performed in 202 patients (119 women, 83 men) between March 1991 and December 2007 using the X-change Femoral Revision System, fresh-frozen morcellised allograft and a cemented polished Exeter stem. All patients were followed prospectively. The mean age of the patients at revision was 65 years (30 to 86). At final review in December 2013 a total of 130 patients with 135 reconstructions (64.9%) were alive and had a non re-revised femoral component after a mean follow-up of 10.6 years (4.7 to 20.9). One patient was lost to follow-up at six years, and their data were included up to this point. Re-operation for any reason was performed in 33 hips (15.9%), in 13 of which the femoral component was re-revised (6.3%). The mean pre-operative Harris hip score was 52 (19 to 95) (n = 73) and improved to 80 (22 to 100) (n = 161) by the last follow-up. Kaplan–Meier survival with femoral re-revision for any reason as the endpoint was 94.9% (95% confidence intervals (CI) 90.2 to 97.4) at ten years; with femoral re-revision for aseptic loosening as the endpoint it was 99.4% (95% CI 95.7 to 99.9); with femoral re-operation for any reason as the endpoint it was 84.5% (95% CI 78.3 to 89.1); and with subsidence ≥ 5 mm it was 87.3% (95% CI 80.5 to 91.8). Femoral revision with the use of impaction allograft bone grafting and a cemented polished stem results in a satisfying survival rate at a mean of ten years’ follow-up.

Cite this article: Bone Joint J 2015; 97-B:771–9.

Cemented femoral stems with force closed fixation designs have shown good clinical results despite high early subsidence. A new triple-tapered stem in this category (C-stem AMT) was introduced in 2005. This study compares this new stem with an established stem of similar design (Exeter) in terms of migration (as measured using radiostereometric analysis), peri-prosthetic bone remodelling (measured using dual energy x-ray densitometry, DXA), Oxford Hip Score, and plain radiographs. . A total of 70 patients (70 hips) with a mean age of 66 years (53 to 78) were followed for two years. Owing to missing data of miscellaneous reasons, the final analysis represents data from 51 (RSA) and 65 (DXA) patients. Both stems showed a typical pattern of migration: Subsidence and retroversion that primarily occurred during the first three months. C-stem AMT subsided less during the first three months (p = 0.01), before stabilising at a subsidence rate similar to the Exeter stem from years one to two. The rate of migration into retroversion was slightly higher for C-stem AMT during the second year (p = 0.03). Whilst there were slight differences in movement patterns between the stems, the C-stem AMT exhibits good early clinical outcomes and displays a pattern of migration and bone remodelling that predicts good clinical performance. Cite this article: Bone Joint J 2015;97-B:755–61

This was a randomised controlled trial studying the safety of a new short metaphyseal fixation (SMF) stem. We hypothesised that it would have similar early clinical results and micromovement to those of a standard-length tapered Synergy metaphyseal fixation stem. Using radiostereometric analysis (RSA) we compared the two stems in 43 patients. A short metaphyseal fixation stem was used in 22 patients and a Synergy stem in 21 patients. No difference was found in the clinical outcomes pre- or post-operatively between groups. RSA showed no significant differences two years post-operatively in mean micromovement between the two stems (except for varus/valgus tilt at p = 0.05) (subsidence 0.94 mm (sd 1.71) vs 0.32 mm (sd 0.45), p = 0.66; rotation 0.96° (sd 1.49) vs 1.41° (sd 2.95), p = 0.88; and total migration 1.09 mm (sd 1.74) vs 0.73 mm (sd 0.72), p = 0.51). A few stems (four SMF and three Synergy) had initial migration > 1.0 mm but stabilised by three to six months, with the exception of one SMF stem which required revision three years post-operatively. For most stems, total micromovement was very low at two years (subsidence < 0.5 mm, rotation < 1.0°, total migration < 0.5 mm), which was consistent with osseous ingrowth. The small sample makes it difficult to confirm the universal applicability of or elucidate the potential contraindications to the use of this particular new design of stem.

Cite this article: Bone Joint J 2015; 97-B:595–602.

Femoral stem version has a major influence on impingement and early post-operative stability after total hip arthroplasty (THA).

The main objective of this study was to evaluate the validity of a novel radiological method for measuring stem version. Anteroposterior (AP) radiographs and three-dimensional CT scans were obtained for 115 patients (female/male 63/72, mean age 62.5 years (50 to 75)) who had undergone minimally invasive, cementless THA. Stem version was calculated from the AP hip radiograph by rotation-based change in the projected prosthetic neck–shaft (NSA*) angle using the mathematical formula ST = arcos [tan (NSA*) / tan (135)]. We used two independent observers who repeated the analysis after a six-week interval. Radiological measurements were compared with 3D-CT measurements by an independent, blinded external institute.

We found a mean difference of 1.2° (sd 6.2) between radiological and 3D-CT measurements of stem version. The correlation between the mean radiological and 3D-CT stem torsion was r = 0.88 (p < 0.001). The intra- (intraclass correlation coefficient ≥ 0.94) and inter-observer agreement (mean concordance correlation coefficient = 0.87) for the radiological measurements were excellent.

We found that femoral tilt was associated with the mean radiological measurement error (r = 0.22, p = 0.02).

The projected neck–shaft angle is a reliable method for measuring stem version on AP radiographs of the hip after a THA. However, a highly standardised radiological technique is required for its precise measurement.

Cite this article: Bone Joint J 2015; 97-B:306–11.

Revision total hip arthroplasty (THA) is challenging when there is severe loss of bone in the proximal femur. The purpose of this study was to evaluate the clinical and radiographic outcomes of revision THA in patients with severe proximal femoral bone loss treated with a fluted, tapered, modular femoral component. Between January 1998 and December 2004, 92 revision THAs were performed in 92 patients using a single fluted, tapered, modular femoral stem design. Pre-operative diagnoses included aseptic loosening, infection and peri-prosthetic fracture. Bone loss was categorised pre-operatively as Paprosky types III-IV, or Vancouver B3 in patients with a peri-prosthetic fracture. The mean clinical follow-up was 6.4 years (2 to 12). A total of 47 patients had peri-operative complications, 27 of whom required further surgery. However, most of these further operations involved retention of a well-fixed femoral stem, and 88/92 femoral components (97%) remained in situ. Of the four components requiring revision, three were revised for infection and were well fixed at the time of revision; only one (1%) was revised for aseptic loosening. The most common complications were post-operative instability (17 hips, 19%) and intra-operative femoral fracture during insertion of the stem (11 hips, 12%). Diaphyseal stress shielding was noted in 20 hips (22%). There were no fractures of the femoral component. At the final follow-up 78% of patients had minimal or no pain. . Revision THA in patients with extensive proximal femoral bone loss using the Link MP fluted, tapered, modular stem led to a high rate of osseointegration of the stem at mid-term follow-up. Cite this article: Bone Joint J 2015; 97-B:312–17