Aims

The aim of this study was to assess medium-term improvements following total hip arthroplasty (THA), and to evaluate what effect different preoperative Oxford Hip Score (OHS) thresholds for treatment may have on patients’ access to THA and outcomes.

It has recently been reported that the transverse acetabular ligament (TAL) is helpful in determining the position of the acetabular component in total hip replacement (THR). In this study we used a computer-assisted navigation system to determine whether the TAL is useful as a landmark in THR. The study was carried out in 121 consecutive patients undergoing primary THR (134 hips), including 67 dysplastic hips (50%). There were 26 men (29 hips) and 95 women (105 hips) with a mean age of 60.2 years (17 to 82) at the time of operation. After identification of the TAL, its anteversion was measured intra-operatively by aligning the inferomedial rim of the trial acetabular component with the TAL using computer-assisted navigation. The TAL was identified in 112 hips (83.6%). Intra-observer reproducibility in the measurement of anteversion of the TAL was high, but inter-observer reproducibility was moderate. . Each surgeon was able to align the trial component according to the target value of the angle of anteversion of the TAL, but it was clear that methods may differ among surgeons. Of the measurements of the angle of anteversion of the TAL, 5.4% (6 of 112 hips) were outliers from the safe zone. In summary, we found that the TAL is useful as a landmark when implanting the acetabular component within the safe zone in almost all hips, and to prevent it being implanted in retroversion in all hips, including dysplastic hips. However, as anteversion of the TAL may be excessive in a few hips, it is advisable to pay attention to individual variations, particularly in those with severe posterior pelvic tilt. Cite this article: Bone Joint J 2014;96-B:306–11

Aims

The aim of this study was to determine whether total hip arthroplasty (THA) for chronic hip pain due to unilateral primary osteoarthritis (OA) has a beneficial effect on cognitive performance.

There have been no large comparative studies of the blood levels of metal ions after implantation of commercially available hip resurfacing devices which have taken into account the effects of femoral size and inclination and anteversion of the acetabular component. We present the results in 90 patients with unilateral articular surface replacement (ASR) hip resurfacings (mean time to blood sampling 26 months) and 70 patients with unilateral Birmingham Hip Resurfacing (BHR) implants (mean time 47 months). The whole blood and serum chromium (Cr) and cobalt (Co) concentrations were inversely related to the size of the femoral component in both groups (p < 0.05). Cr and Co were more strongly influenced by the position of the acetabular component in the case of the ASR, with an increase in metal ions observed at inclinations > 45° and anteversion angles of < 10° and > 20°. These levels were only increased in the BHR group when the acetabular component was implanted with an inclination > 55°. A significant relationship was identified between the anteversion of the BHR acetabular component and the levels of Cr and Co (p < 0.05 for Co), with an increase observed at anteversion angles < 10° and > 20°. The median whole blood and serum Cr concentrations of the male ASR patients were significantly lower than those of the BHR men (p < 0.001). This indicates that reduced diametral clearance may equate to a reduction in metal ion concentrations in larger joints with satisfactory orientation of the acetabular component

Aims

The aim of this study was to determine the association between knee alignment and the vertical orientation of the femoral neck in relation to the floor. This could be clinically important because changes of femoral neck orientation might alter chondral joint contact zones and joint reaction forces, potentially inducing problems like pain in pre-existing chondral degeneration. Further, the femoral neck orientation influences the ischiofemoral space and a small ischiofemoral distance can lead to impingement. We hypothesized that a valgus knee alignment is associated with a more vertical orientation of the femoral neck in standing position, compared to a varus knee. We further hypothesized that realignment surgery around the knee alters the vertical orientation of the femoral neck.

Aims

In the native hip, the hip capsular ligaments tighten at the limits of range of hip motion and may provide a passive stabilizing force to protect the hip against edge loading. In this study we quantified the stabilizing force vectors generated by capsular ligaments at extreme range of motion (ROM), and examined their ability to prevent edge loading.

We investigated the development of CT-based bony radiological parameters associated with femoroacetabular impingement (FAI) in a paediatric and adolescent population with no known orthopaedic hip complaints. We retrospectively reformatted and reoriented 225 abdominal CTs into standardised CT pelvic images with neutral pelvic tilt and inclination (244 female and 206 male hips) in patients ranging from two to 19 years of age (mean 10.4 years). The Tönnis angle, acetabular depth ratio, lateral centre–edge angle, acetabular version and α-angle were assessed. Acetabular measurements demonstrated increased acetabular coverage with age and/or progressive ossification of the acetabulum. The α-angle decreased with age and/or progressive cortical bone development and resultant narrowing of the femoral neck. Cam and pincer morphology occurred as early as ten and 12 years of age, respectively, and their prevalence in the adolescent patient population is similar to that reported in the adult literature. Future aetiological studies of FAI will need to focus on the early adolescent population. Cite this article: Bone Joint J 2013;95-B:598–604

Down’s syndrome is associated with a number of musculoskeletal abnormalities, some of which predispose patients to early symptomatic arthritis of the hip. The purpose of the present study was to review the general and hip-specific factors potentially compromising total hip replacement (THR) in patients with Down’s syndrome, as well as to summarise both the surgical techniques that may anticipate the potential adverse impact of these factors and the clinical results reported to date. A search of the literature was performed, and the findings further informed by the authors’ clinical experience, as well as that of the hip replacement in Down Syndrome study group. The general factors identified include a high incidence of ligamentous laxity, as well as associated muscle hypotonia and gait abnormalities. Hip-specific factors include: a high incidence of hip dysplasia, as well as a number of other acetabular, femoral and combined femoroacetabular anatomical variations. Four studies encompassing 42 hips, which reported the clinical outcomes of THR in patients with Down’s syndrome, were identified. All patients were successfully treated with standard acetabular and femoral components. The use of supplementary acetabular screw fixation to enhance component stability was frequently reported. The use of constrained liners to treat intra-operative instability occurred in eight hips. Survival rates of between 81% and 100% at a mean follow-up of 105 months (6 to 292) are encouraging. Overall, while THR in patients with Down’s syndrome does present some unique challenges, the overall clinical results are good, providing these patients with reliable pain relief and good function. Cite this article: Bone Joint J 2013;95-B, Supple A:41–5

We reviewed 123 second-generation uncemented total hip replacements performed on 115 patients by a single surgeon between 1993 and 1994. The acetabular component used in all cases was a fully porous-coated threaded hemispheric titanium shell (T-Tap ST) with a calcium ion stearate-free, isostatically compression-moulded polyethylene liner. The titanium femoral component used was a Taperloc with a reduced distal stem. No patient was lost to follow-up. Complete clinical and radiological follow-up was obtained for all 123 hips at a mean of 14 years (12 to 16). One femoral component was revised after a fracture, and three acetabular components for aseptic loosening. No additional femoral or acetabular components were judged loose by radiological criteria. Mild proximal femoral osteolysis was identified in two hips and minor acetabular osteolysis was present in four. The mean rate of penetration of the femoral head was 0.036 mm/year (0.000 to 0.227). These findings suggest that refinements in component design may be associated with excellent long-term fixation in cementless primary total hip replacement

Finite element analysis was used to examine the initial stability after hip resurfacing and the effect of the procedure on the contact mechanics at the articulating surfaces. Models were created with the components positioned anatomically and loaded physiologically through major muscle forces. Total micromovement of less than 10 μm was predicted for the press-fit acetabular components models, much below the 50 μm limit required to encourage osseointegration. Relatively high compressive acetabular and contact stresses were observed in these models. The press-fit procedure showed a moderate influence on the contact mechanics at the bearing surfaces, but produced marked deformation of the acetabular components. No edge contact was predicted for the acetabular components studied. It is concluded that the frictional compressive stresses generated by the 1 mm to 2 mm interference-fit acetabular components, together with the minimal micromovement, would provide adequate stability for the implant, at least in the immediate post-operative situation

Aims

Iliosacral sarcoma resections have been shown to have high rates of local recurrence (LR) and poor overall survival. There is also no universal classification for the resection of pelvic sarcomas invading the sacrum. This study proposes a novel classification system and analyzes the survival and risk of recurrence, when using this system.

Aims. The aim of this study was to determine the stability of a new short femoral stem compared with a conventional femoral stem in patients undergoing cementless total hip arthroplasty (THA), in a prospective randomized controlled trial using radiostereometric analysis (RSA). Patients and Methods. A total of 53 patients were randomized to receive cementless THA with either a short femoral stem (MiniHip, 26 patients, mean age: 52 years, nine male) or a conventional length femoral stem (MetaFix, 23 patients, mean age: 53 years, 11 male). All patients received the same cementless acetabular component. Two-year follow-up was available on 38 patients. Stability was assessed through migration and dynamically inducible micromotion. Radiographs for RSA were taken postoperatively and at three, six, 12, 18, and 24 months. Results. At two years, there was significantly less subsidence (inferior migration) of the short femoral stem (head, 0.26 mm, 95% confidence interval (CI) 0.08 to 0.43, . sd. 0.38; tip, 0.11 mm, 95% CI -0.08 to 0.31, . sd. 0.42) compared with the conventional stem (head, 0.62 mm, 95% CI 0.34 to 0.90, . sd. 0.56, p = 0.02; tip, 0.43 mm, 95% CI 0.21 to 0.65, . sd. 0.44, p = 0.03). There was no significant difference in dynamically inducible micromotion, rate of complications or functional outcome. Conclusion. This study demonstrates that the short femoral stem has a stable and predictable migration. However, longer-term survival analysis still needs to be determined. Cite this article: Bone Joint J 2018;100-B:1148–56

Aims

Total hip arthroplasty (THA) in patients with post-polio residual paralysis (PPRP) is challenging. Despite relief in pain after THA, pre-existing muscle imbalance and altered gait may cause persistence of difficulty in walking. The associated soft tissue contractures not only imbalances the pelvis, but also poses the risk of dislocation, accelerated polyethylene liner wear, and early loosening.

Aims

Femoral bone preparation using compaction technique has been shown to preserve bone and improve implant fixation in animal models. No long-term clinical outcomes are available. There are no significant long-term differences between compaction and broaching techniques for primary total hip arthroplasty (THA) in terms of migration, clinical, and radiological outcomes.

Aims

The use of 3D printing has become increasingly popular and has been widely used in orthopaedic surgery. There has been a trend towards an increasing number of publications in this field, but existing literature incorporates limited high-quality studies, and there is a lack of reports on outcomes. The aim of this study was to perform a scoping review with Level I evidence on the application and effectiveness of 3D printing.

Between 1980 and 2000, 63 support rings were used in the management of acetabular deficiency in a series of 60 patients, with a mean follow-up of 8.75 years (2 months to 23.8 years). There was a minimum five-year follow-up for successful reconstructions. The indication for revision surgery was aseptic loosening in 30 cases and infection in 33. All cases were Paprosky III defects; IIIA in 33 patients (52.4%) and IIIB in 30 (47.6%), including four with pelvic dissociation. A total of 26 patients (43.3%) have died since surgery, and 34 (56.7%) remain under clinical review. With acetabular revision for infection or aseptic loosening as the definition of failure, we report success in 53 (84%) of the reconstructions. A total of 12 failures (19%) required further surgery, four (6.3%) for aseptic loosening of the acetabular construct, six (9.5%) for recurrent infection and two (3.2%) for recurrent dislocation requiring captive components. Complications, seen in 11 patients (18.3%), included six femoral or sciatic neuropraxias which all resolved, one grade III heterotopic ossification, one on-table acetabular revision for instability, and three early post-operative dislocations managed by manipulation under anaesthesia, with no further instability. We recommend support rings and morcellised bone graft for significant acetabular bone deficiency that cannot be reconstructed using mesh

Aims. To report our experience with trunnion corrosion following metal-on-polyethylene total hip arthroplasty, in particular to report the spectrum of presentation and determine the mean time to presentation. Patients and Methods. We report the presenting symptoms and signs, intraoperative findings, and early results and complications of operative treatment in nine patients with a mean age of 74 years (60 to 86). The onset of symptoms was at a mean of seven years (3 to 18) after index surgery. Results. Patients presented with a variety of symptoms including pain, limp and rash. The preoperative mean serum cobalt level was 7.1 ppb (2.2 to 12.8) and mean serum chromium level was 2.2 ppb (0.5 to 5.2). Metal artifact reduction sequence (MARS) MRI showed fluid collection and possible pseudotumour formation in five hips, fluid collection in two hips, and synovitis/debris in one hip, with no MRI in one patient. Acetabular revision was performed in three patients, six patients underwent liner and head exchange only. The postoperative metal levels decreased in all patients: mean cobalt 0.5 ppb (0 to 1.8) and mean chromium 0.9 ppb (0 to 2.6) at a mean of five months (3 to 8) postoperatively. Seven patients had good pain relief and no complications at one year. There were two major complications requiring reoperation: acute infection at six weeks, for which the patient required two-stage reimplantation; and recurrent dislocation, for which the patient was revised to a dual mobility component. Conclusion. Trunnion corrosion in metal-on-polyethylene THA has a range of presenting symptoms, and may present later than previously described. A high index of suspicion is warranted, and serum cobalt and chromium levels are recommended for diagnosis. Patients should be counselled about possible postoperative complications. Cite this article: Bone Joint J 2018;100-B:898–902

Aims

The aim of our study was to investigate the effect of asymmetric crosslinked polyethylene liner use on the risk of revision of cementless and hybrid total hip arthroplasties (THAs).

We retrospectively reviewed 44 consecutive patients (50 hips) who underwent acetabular re-revision after a failed previous revision that had been performed using structural or morcellised allograft bone, with a cage or ring for uncontained defects. Of the 50 previous revisions, 41 cages and nine rings were used with allografts for 14 minor-column and 36 major-column defects. We routinely assessed the size of the acetabular bone defect at the time of revision and re-revision surgery. This allowed us to assess whether host bone stock was restored. We also assessed the outcome of re-revision surgery in these circumstances by means of radiological characteristics, rates of failure and modes of failure. We subsequently investigated the factors that may affect the potential for the restoration of bone stock and the durability of the re-revision reconstruction using multivariate analysis. At the time of re-revision, there were ten host acetabula with no significant defects, 14 with contained defects, nine with minor-column, seven with major-column defects and ten with pelvic discontinuity. When bone defects at re-revision were compared with those at the previous revision, there was restoration of bone stock in 31 hips, deterioration of bone stock in nine and remained unchanged in ten. This was a significant improvement (p <  0.001). Morselised allografting at the index revision was not associated with the restoration of bone stock. . In 17 hips (34%), re-revision was possible using a simple acetabular component without allograft, augments, rings or cages. There were 47 patients with a mean follow-up of 70 months (6 to 146) available for survival analysis. Within this group, the successful cases had a minimum follow-up of two years after re-revision. There were 22 clinical or radiological failures (46.7%), 18 of which were due to aseptic loosening. The five and ten year Kaplan–Meier survival rate was 75% (95% CI, 60 to 86) and 56% (95% CI, 40 to 70) respectively with aseptic loosening as the endpoint. The rate of aseptic loosening was higher for hips with pelvic discontinuity (p = 0.049) and less when the allograft had been in place for longer periods (p = 0.040). . The use of a cage or ring over structural allograft bone for massive uncontained defects in acetabular revision can restore host bone stock and facilitate subsequent re-revision surgery to a certain extent. Cite this article: Bone Joint J 2014;96-B:319–24