Advances in the treatment of periprosthetic joint infections of the hip have once more pushed prosthesis preserving techniques into the limelight. At the same time, the common infecting organisms are evolving to become more resistant to conventional antimicrobial agents. Whilst the epidemiology of resistant staphylococci is changing, a number of recent reports have advocated the use of irrigation and debridement and one-stage revision for the treatment of periprosthetic joint infections due to resistant organisms. This review presents the available evidence for the treatment of periprosthetic joint infections of the hip, concentrating in particular on methicillin resistant staphylococci.

Cite this article: Bone Joint J 2014;96-B(11 Suppl A):60–5.

We investigated the changes seen on serial metal artefact reduction magnetic resonance imaging scans (MARS-MRI) of metal-on-metal total hip arthroplasties (MoM THAs). In total 155 THAs, in 35 male and 100 female patients (mean age 70.4 years, 42 to 91), underwent at least two MRI scans at a mean interval of 14.6 months (2.6 to 57.1), at a mean of 48.2 months (3.5 to 93.3) after primary hip surgery. Scans were graded using a modification of the Oxford classification. Progression of disease was defined as an increase in grade or a minimum 10% increase in fluid lesion volume at second scan. A total of 16 hips (30%) initially classified as ‘normal’ developed an abnormality on the second scan. Of those with ‘isolated trochanteric fluid’ 9 (47%) underwent disease progression, as did 7 (58%) of ‘effusions’. A total of 54 (77%) of hips initially classified as showing adverse reactions to metal debris (ARMD) progressed, with higher rates of progression in higher grades. Disease progression was associated with high blood cobalt levels or an irregular pseudocapsule lining at the initial scan. There was no association with changes in functional scores. Adverse reactions to metal debris in MoM THAs may not be as benign as previous reports have suggested. Close radiological follow-up is recommended, particularly in high-risk groups.

Cite this article: Bone Joint J 2015;97-B:1328–37.

The December 2014 Knee Roundup³⁶⁰ looks at: national guidance on arthroplasty thromboprophylaxis is effective; unicompartmental knee replacement has the edge in terms of short-term complications; stiff knees, timing and manipulation; neuropathic pain and total knee replacement; synovial fluid α-defensin and CRP: a new gold standard in joint infection diagnosis?; how to assess anterior knee pain?; where is the evidence? Five new implants under the spotlight; and a fresh look at ACL reconstruction

Acetabular bone loss is a challenging problem facing the revision total hip replacement surgeon. Reconstruction of the acetabulum depends on the presence of anterosuperior and posteroinferior pelvic column support for component fixation and stability. The Paprosky classification is most commonly used when determining the location and degree of acetabular bone loss. Augments serve the function of either providing primary construct stability or supplementary fixation.

When a pelvic discontinuity is encountered we advocate the use of an acetabular distraction technique with a jumbo cup and modular porous metal acetabular augments for the treatment of severe acetabular bone loss and associated chronic pelvic discontinuity.

Cite this article: Bone Joint J 2014;96-B(11 Suppl A):36–42.

The differential diagnosis of the painful total hip arthroplasty (resurfacing or total hip) includes infection, failure of fixation (loosening), tendinitis, bursitis, synovitis, adverse local tissue reaction (ALTR) to cobalt-chromium alloys, and non-hip issues, such as spinal disorders, hernia, gynecologic, and other pelvic pain. Assuming that the hip is the source of pain, the first level question is prosthetic or non-prosthetic pain generator? The second level prosthetic question is septic or aseptic? The third level question (aseptic hips) is well-fixed or loose? ALTR is best diagnosed by cross-sectional imaging. Successful treatment is dependent on correct identification and elimination of the pain generator. Treatment recommendations for ALTR and taper corrosion are evolving.

Aims

We assessed the difference in hospital based and early clinical outcomes between the direct anterior approach and the posterior approach in patients who undergo total hip arthroplasty (THA).

The February 2015 Knee Roundup³⁶⁰ looks at: Intra-operative sensors for knee balance; Mobile bearing no advantage; Death and knee replacement: a falling phenomenon; The swings and roundabouts of unicompartmental arthroplasty; Regulation, implants and innovation; The weight of arthroplasty responsibility!; BMI in arthroplasty

We evaluated the rates of survival and cause of revision of seven different brands of cemented primary total knee replacement (TKR) in the Norwegian Arthroplasty Register during the years 1994 to 2009. Revision for any cause, including resurfacing of the patella, was the primary endpoint. Specific causes of revision were secondary outcomes.

Three posterior cruciate-retaining (PCR) fixed modular-bearing TKRs, two fixed non-modular bearing PCR TKRs and two mobile-bearing posterior cruciate-sacrificing TKRs were investigated in a total of 17 782 primary TKRs. The median follow-up for the implants ranged from 1.8 to 6.9 years. Kaplan-Meier 10-year survival ranged from 89.5% to 95.3%. Cox’s relative risk (RR) was calculated relative to the fixed modular-bearing Profix knee (the most frequently used TKR in Norway), and ranged from 1.1 to 2.6. The risk of revision for aseptic tibial loosening was higher in the mobile-bearing LCS Classic (RR 6.8 (95% confidence interval (CI) 3.8 to 12.1)), the LCS Complete (RR 7.7 (95% CI 4.1 to 14.4)), the fixed modular-bearing Duracon (RR 4.5 (95% CI 1.8 to 11.1)) and the fixed non-modular bearing AGC Universal TKR (RR 2.5 (95% CI 1.3 to 5.1)), compared with the Profix. These implants (except AGC Universal) also had an increased risk of revision for femoral loosening (RR 2.3 (95% CI 1.1 to 4.8), RR 3.7 (95% CI 1.6 to 8.9), and RR 3.4 (95% CI 1.1 to 11.0), respectively). These results suggest that aseptic loosening is related to design in TKR.

Cite this article: Bone Joint J 2013;95-B:636–42.

We determined the efficacy of a devitalised autograft (n = 13) and allograft (n = 16) cortical strut bone graft combined with long-stem endoprosthetic reconstruction in the treatment of massive tumours of the lower limb. A total of 29 patients (18 men:11 women, mean age 20.1 years (12 to 45) with a ratio of length of resection to that of the whole prosthesis of > 50% were treated between May 2003 and May 2012. The mean follow-up was 47 months (15 to 132). The stem of the prosthesis was introduced through bone graft struts filled with cement, then cemented into the residual bone. Bone healing was achieved in 23 patients (86%). The mean Musculoskeletal Tumour Society functional score was 85% (57 to 97). The five-year survival rate of the endoprostheses was 81% (95% confidence intervals 67.3 to 92.3). The mean length of devitalised autografts and allografts was 8.6 cm (5 to 15), which increased the ratio of the the length of the stem of the prosthesis to that of the whole length of the prosthesis from a theoretical 35% to an actual 55%.

Cortical strut bone grafting and long-stem endoprosthetic reconstruction is an option for treating massive segmental defects following resection of a tumour in the lower limb. Patients can regain good function with a low incidence of aseptic loosening. The strut graft and the residual bone together serve as a satisfactory bony environment for a revision prosthesis, if required, once union is achieved.

Cite this article: Bone Joint J 2015;97-B:544–9.

Large ceramic femoral heads offer several advantages that are potentially advantageous to patients undergoing both primary and revision total hip replacement. Many high-quality studies have demonstrated the benefit of large femoral heads in reducing post-operative instability. Ceramic femoral heads may also offer an advantage in reducing polyethylene wear that has been reported in vitro and is starting to become clinically apparent in mid-term clinical outcome studies. Additionally, the risk of taper corrosion at a ceramic femoral head–neck junction is clearly lower than when using a metal femoral head. With improvements in the material properties of both modern ceramic femoral heads and polyethylene acetabular liners that have reduced the risk of mechanical complications, large ceramic heads have gained popularity in recent years.

Cite this article: Bone Joint J 2013;95-B, Supple A:63–6.

We reviewed the outcome of 69 uncemented, custom-made, distal femoral endoprosthetic replacements performed in 69 patients between 1994 and 2006. There were 31 women and 38 men with a mean age at implantation of 16.5 years (5 to 37). All procedures were performed for primary malignant bone tumours of the distal femur. At a mean follow-up of 124.2 months (4 to 212), 53 patients were alive, with one patient lost to follow-up. All nine implants (13.0%) were revised due to aseptic loosening at a mean of 52 months (8 to 91); three implants (4.3%) were revised due to fracture of the shaft of the prosthesis and three patients (4.3%) had a peri-prosthetic fracture. Bone remodelling associated with periosteal cortical thinning adjacent to the uncemented intramedullary stem was seen in 24 patients but this did not predispose to failure. All aseptically loose implants in this series were diagnosed to be loose within the first five years.

The results from this study suggest that custom-made uncemented distal femur replacements have a higher rate of aseptic loosening compared to published results for this design when used with cemented fixation. Loosening of uncemented replacements occurs early indicating that initial fixation of the implant is crucial.

Cite this article: Bone Joint J 2014;96-B:263–9.

Revision total hip arthroplasty (THA) is projected to increase by 137% from the years 2005 to 2030. Reconstruction of the femur with massive bone loss can be a formidable undertaking. The goals of revision surgery are to create a stable construct, preserve bone and soft tissues, augment deficient host bone, improve function, provide a foundation for future surgery, and create a biomechanically restored hip. Options for treatment of the compromised femur include: resection arthroplasty, allograft prosthetic composite (APC), proximal femoral replacement, cementless fixation with a modular tapered fluted stem, and impaction grafting. The purpose of this article is to review the treatment options along with their associated outcomes in the more severe femoral defects (Paprosky types IIIb and IV) in revision THA.

We evaluated an operative technique, described by the Exeter Hip Unit, to assist accurate introduction of the femoral component. We assessed whether it led to a reduction in the rate of leg-length discrepancy after total hip arthroplasty (THA).

A total of 100 patients undergoing THA were studied retrospectively; 50 were undertaken using the test method and 50 using conventional methods as a control group. The groups were matched with respect to patient demographics and the grade of surgeon. Three observers measured the depth of placement of the femoral component on post-operative radiographs and measured the length of the legs.

There was a strong correlation between the depth of insertion of the femoral component and the templated depth in the test group (R = 0.92), suggesting accuracy of the technique. The mean leg-length discrepancy was 5.1 mm (0.6 to 21.4) pre-operatively and 1.3 mm (0.2 to 9.3) post-operatively. There was no difference between Consultants and Registrars as primary surgeons. Agreement between the templated and post-operative depth of insertion was associated with reduced post-operative leg-length discrepancy. The intra-class coefficient was R ≥ 0.88 for all measurements, indicating high observer agreement. The post-operative leg-length discrepancy was significantly lower in the test group (1.3 mm) compared with the control group (6.3 mm, p < 0.001).

The Exeter technique is reproducible and leads to a lower incidence of leg-length discrepancy after THA.

Cite this article: Bone Joint J 2015;97-B:154–9.

A key to the success of revision total knee arthroplasty (TKA) is a safe surgical approach using an exposure that minimises complications. In most patients, a medial parapatellar arthrotomy with complete synovectomy is sufficient. If additional exposure is needed, a quadriceps snip performed through the quadriceps tendon often provides the additional exposure required. It is simple to perform and does not alter the post-operative rehabilitative protocol. In rare cases, in which additional exposure is needed, or when removal of a cemented long-stemmed tibial component is required, a tibial tubercle osteotomy (TTO) may be used. Given the risk of post-operative extensor lag, a V-Y quadricepsplasty is rarely indicated and usually considered only if TTO is not possible.

Cite this article: Bone Joint J 2016;98-B(1 Suppl A):113–15.

The term developmental dysplasia of the hip (DDH) describes a spectrum of disorders that results in abnormal development of the hip joint. If not treated successfully in childhood, these patients may go on to develop hip symptoms and/or secondary osteoarthritis in adulthood. In this review we describe the altered anatomy encountered in adults with DDH along with the management options, and the challenges associated with hip arthroscopy, osteotomies and arthroplasty for the treatment of DDH in young adults.

Cite this article: Bone Joint J 2013;95-B:732–7.

The custom triflange is a patient-specific implant for the treatment of severe bone loss in revision total hip arthroplasty (THA). Through a process of three-dimensional modelling and prototyping, a hydroxyapatite-coated component is created for acetabular reconstruction. There are seven level IV studies describing the clinical results of triflange components. The most common complications include dislocation and infection, although the rates of implant removal are low. Clinical results are promising given the challenging problem. We describe the design, manufacture and implantation process and review the clinical results, contrasting them to other methods of acetabular reconstruction in revision THA.

Cite this article: Bone Joint J 2016;98-B(1 Suppl A):68–72.

Periprosthetic joint infection (PJI) complicates between 0.5% and 1.2% primary total hip arthroplasties (THAs) and may have devastating consequences. The traditional assessment of patients suffering from PJI has involved the serological study of inflammatory markers and microbiological analysis of samples obtained from the joint space. Treatment has involved debridement and revision arthroplasty performed in either one or two stages.

We present an update on the burden of PJI, strategies for its diagnosis and treatment, the challenge of resistant organisms and the need for definitive evidence to guide the treatment of PJI after THA.

Cite this article: Bone Joint J 2016;98-B(1 Suppl A):27–30.

The August 2013 Hip & Pelvis Roundup³⁶⁰ looks at: are we getting it right first time?; tantalum augments in revision hip surgery; lower wear in dual mobility?; changing faces changes outcomes; synovial fluid aspiration in MOM hips; taper disease: the new epidemic of hip surgery; the super-obese and THR; and whether well fixed stems can remain in infected hips

Version of the femoral stem is an important factor influencing the risk of dislocation after total hip replacement (THR) as well as the position of the acetabular component. However, there is no radiological method of measuring stem anteversion described in the literature. We propose a radiological method to measure stem version and have assessed its reliability and validity. In 36 patients who underwent THR, a hip radiograph and CT scan were taken to measure stem anteversion. The radiograph was a modified Budin view. This is taken as a posteroanterior radiograph in the sitting position with 90° hip flexion and 90° knee flexion and 30° hip abduction. The angle between the stem-neck axis and the posterior intercondylar line was measured by three independent examiners. The intra- and interobserver reliabilities of each measurement were examined. The radiological measurements were compared with the CT measurements to evaluate their validity. The mean radiological measurement was 13.36° (sd 6.46) and the mean CT measurement was 12.35° (sd 6.39) (p = 0.096). The intra- and interobserver reliabilities were excellent for both measurements. The radiological measurements correlated well with the CT measurements (p = 0.001, r = 0.877). The modified Budin method appears reliable and valid for the measurement of femoral stem anteversion.

Cite this article: Bone Joint J 2013;95-B:877–80.