The lateral compartment is predominantly affected in approximately 10% of patients with osteoarthritis of the knee. The anatomy, kinematics and loading during movement differ considerably between medial and lateral compartments of the knee. This in the main explains the relative protection of the lateral compartment compared with the medial compartment in the development of osteoarthritis. The aetiology of lateral compartment osteoarthritis can be idiopathic, usually affecting the femur, or secondary to trauma commonly affecting the tibia. Surgical management of lateral compartment osteoarthritis can include osteotomy, unicompartmental knee replacement and total knee replacement. This review discusses the biomechanics, pathogenesis and development of lateral compartment osteoarthritis and its management.

Cite this article: Bone Joint J 2013;95-B:436–44.

The April 2015 Knee Roundup360 looks at: Genetic determinants of ACL strength; TKA outcomes influenced by prosthesis; Single- or two-stage revision for infected TKA?; Arthroscopic meniscectomy: a problem that just won’t go away!; Failure in arthroscopic ACL reconstruction; ACL reconstruction in the over 50s?; Knee arthroplasty for early osteoarthritis; All inside meniscal repair; Steroids, thrombogenic markers and TKA

Bone loss in the proximal tibia and distal femur is frequently encountered in revision knee replacement surgery. The various options for dealing with this depend on the extent of any bone loss. We present our results with the use of cementless metaphyseal metal sleeves in 103 patients (104 knees) with a mean follow-up of 43 months (30 to 65). At final follow-up, sleeves in 102 knees had good osseointegration. Two tibial sleeves were revised for loosening, possibly due to infection.

The average pre-operative Oxford Knee Score was 23 (11 to 36) and this improved to 32 (15 to 46) post-operatively. These early results encourage us to continue with the technique and monitor the outcomes in the long term.

Cite this article: Bone Joint J 2013;95-B:1640–4.

The outcome of total knee replacement (TKR) using components designed to increase the range of flexion is not fully understood. The short- to mid-term risk of aseptic revision in high flexion TKR was evaluated. The endpoint of the study was aseptic revision and the following variables were investigated: implant design (high flexion vs non-high flexion), the thickness of the tibial insert (≤ 14 mm vs > 14 mm), cruciate ligament (posterior stabilised (PS) vs cruciate retaining), mobility (fixed vs rotating), and the manufacturer (Zimmer, Smith & Nephew and DePuy). Covariates included patient, implant, surgeon and hospital factors. Marginal Cox proportional hazard models were used.

In a cohort of 64 000 TKRs, high flexion components were used in 8035 (12.5%). The high flexion knees with tibial liners of thickness > 14 mm had a density of revision of 1.45/100 years of observation, compared with 0.37/100 in non-high flexion TKR with liners ≤ 14 mm thick. Relative to a standard fixed PS TKR, the NexGen (Zimmer, Warsaw, Indiana) Gender Specific Female high flexion fixed PS TKR had an increased risk of revision (hazard ratio (HR) 2.27 (95% confidence interval (CI) 1.48 to 3.50)), an effect that was magnified when a thicker tibial insert was used (HR 8.10 (95% CI 4.41 to 14.89)).

Surgeons should be cautious when choosing high flexion TKRs, particularly when thicker tibial liners might be required.

Cite this article: Bone Joint J 2014;96-B:217–23.

Aims

The aims of this study were to describe the course of non-operatively managed, bilateral Perthes’ disease, and to determine specific prognostic factors for the radiographic and clinical outcome.

Objectives

During open orthopaedic surgery, joints may be exposed to air, potentially leading to cartilage drying and chondrocyte death, however, the long-term effects of joint drying in vivo are poorly understood. We used an animal model to investigate the subsequent effects of joint drying on cartilage and chondrocytes.

The Swansea Morriston Achilles Rupture Treatment (SMART) programme was introduced in 2008. This paper summarises the outcome of this programme. Patients with a rupture of the Achilles tendon treated in our unit follow a comprehensive management protocol that includes a dedicated Achilles clinic, ultrasound examination, the use of functional orthoses, early weight-bearing, an accelerated exercise regime and guidelines for return to work and sport. The choice of conservative or surgical treatment was based on ultrasound findings.

The rate of re-rupture, the outcome using the Achilles Tendon Total Rupture Score (ATRS) and the Achilles Tendon Repair Score, (AS), and the complications were recorded. An elementary cost analysis was also performed.

Between 2008 and 2014 a total of 273 patients presented with an acute rupture 211 of whom were managed conservatively and 62 had surgical repair. There were three re-ruptures (1.1%). There were 215 men and 58 women with a mean age of 46.5 years (20 to 86). Functional outcome was satisfactory. Mean ATRS and AS at four months was 53.0 (sd 14), 64.9 (sd 15) (n = 135), six months 67.8 (sd 16), 73.8 (sd 15) (n = 103) and nine months (72.4; sd 14) 72.3 (sd 13) (n = 43). The programme realised estimated cost savings exceeding £91 000 per annum.

The SMART programme resulted in a low rate of re-rupture, a satisfactory outcome, a reduced rate of surgical intervention and a reduction in healthcare costs.

Cite this article: Bone Joint J 2015; 97-B:510–15.

Mobile-bearing (MB) total knee replacement (TKR) was introduced to reduce the risk of aseptic loosening and wear of polyethylene inserts. However, no consistent clinical advantages of mobile- over fixed-bearing (FB) TKR have been found. In this study we evaluated whether mobile bearings have an advantage over fixed bearings with regard to revision rates and clinical outcome scores. Furthermore, we determined which modifying variables affected the outcome.

A systematic search of the literature was conducted to collect clinical trials comparing MB and FB in primary TKR. The primary outcomes were revision rates for any reason, aseptic loosening and wear. Secondary outcomes included range of movement, Knee Society score (KSS), Oxford knee score (OKS), Short-Form 12 (SF-12) score and radiological parameters. Meta-regression techniques were used to explore factors modifying the observed effect.

Our search yielded 1827 publications, of which 41 studies met our inclusion criteria, comprising over 6000 TKRs. Meta-analyses showed no clinically relevant differences in terms of revision rates, clinical outcome scores or patient-reported outcome measures between MB and FB TKRs. It appears that theoretical assumptions of superiority of MB over FB TKR are not borne out in clinical practice.

Cite this article: Bone Joint J 2013;95-B:1209–16.

Aims

The primary aim of this study was to analyse the position of the acetabular and femoral components in total hip arthroplasty undertaken using an anterior surgical approach.

Aims

This retrospective cohort study compared the results of vascularised and non-vascularised anterior sliding tibial grafts for the treatment of osteoarthritis (OA)of the ankle secondary to osteonecrosis of the talus.

Aims

The highly cross-linked polyethylene Exeter RimFit flanged cemented acetabular component was introduced in the United Kingdom in 2010. This study aimed to examine the rates of emergence of radiolucent lines observed when the Rimfit acetabular component was implanted at total hip arthroplasty (THA) using two different techniques: firstly, the ‘rimcutter’ technique in which the flange sits on a pre-prepared acetabular rim; and secondly, the ‘trimmed flange’ technique in which the flange is trimmed and the acetabular component is seated inside the rim of the acetabulum.

Tapered fluted titanium stems are increasingly used for femoral revision arthroplasty. They are available in modular and non-modular forms. Modularity has advantages when the bone loss is severe, the proximal femur is mis shapen or the surgeon is unfamiliar with the implant, but it introduces the risk of fracture of the stem at the junction between it and the proximal body segment. For that reason, and while awaiting intermediate-term results of more recently introduced designs of this junction, non-modularity has attracted attention, at least for straightforward revision cases.

We review the risks and causes of fracture of tapered titanium modular revision stems and present an argument in favour of the more selective use of modular designs.

Cite this article: Bone Joint J 2016;98-B(1 Suppl A):50–3.

There is little evidence on the cost effectiveness of different brands of hip prostheses. We compared lifetime cost effectiveness of frequently used brands within types of prosthesis including cemented (Exeter V40 Contemporary, Exeter V40 Duration and Exeter V40 Elite Plus Ogee), cementless (Corail Pinnacle, Accolade Trident, and Taperloc Exceed) and hybrid (Exeter V40 Trilogy, Exeter V40 Trident, and CPT Trilogy). We used data from three linked English national databases to estimate the lifetime risk of revision, quality-adjusted life years (QALYs) and cost.

For women with osteoarthritis aged 70 years, the Exeter V40 Elite Plus Ogee had the lowest risk of revision (5.9% revision risk, 9.0 QALYs) and the CPT Trilogy had the highest QALYs (10.9% revision risk, 9.3 QALYs). Compared with the Corail Pinnacle (9.3% revision risk, 9.22 QALYs), the most commonly used brand, and assuming a willingness-to-pay of £20 000 per QALY gain, the CPT Trilogy is most cost effective, with an incremental net monetary benefit of £876. Differences in cost effectiveness between the hybrid CPT Trilogy and Exeter V40 Trident and the cementless Corail Pinnacle and Taperloc Exceed were small, and a cautious interpretation is required, given the limitations of the available information.

However, it is unlikely that cemented brands are among the most cost effective. Similar patterns of results were observed for men and other ages. The gain in quality of life after total hip arthroplasty, rather than the risk of revision, was the main driver of cost effectiveness.

Cite this article: Bone Joint J 2015;97-B:762–70.

Current analysis of unicondylar knee replacements (UKRs) by national registries is based on the pooled results of medial and lateral implants. Consequently, little is known about the differential performance of medial and lateral replacements and the influence of each implant type within these pooled analyses. Using data from the National Joint Registry for England and Wales (NJR) we aimed to determine the proportion of UKRs implanted on the lateral side of the knee, and their survival and reason for failure compared with medial UKRs. By combining information on the side of operation with component details held on the NJR, we were able to determine implant laterality (medial versus lateral) for 32 847 of the 35 624 unicondylar replacements (92%) registered before December 2010. Of these, 2052 (6%) were inserted on the lateral side of the knee. The rates of survival at five years were 93.1% (95% confidence interval (CI) 92.7 to 93.5) for medial and 93.0% (95% CI 91.1 to 94.9) for lateral UKRs (p = 0.49). The rates of failure remained equivalent after adjusting for patient age, gender, American Society of Anesthesiologists (ASA) grade, indication for surgery and implant design using Cox’s proportional hazards method (hazard ratio for lateral relative to medial replacement = 0.88 (95% CI 0.69 to 1.13); p = 0.32). Aseptic loosening/lysis and unexplained pain were the main reasons for revision in both groups, although the reasons did vary depending on whether a mobile- or a fixed-bearing design was used. At a maximum of eight years the mid-term survival rates of medial and lateral UKRs are similar.

Objectives

The objective of this study was to determine if combining variations in mixing technique of antibiotic-impregnated polymethylmethacrylate (PMMA) cement with low frequency ultrasound (LFUS) improves antibiotic elution during the initial high phase (Phase I) and subsequent low phase (Phase II) while not diminishing mechanical strength.

Objectives

Sagittal alignment of the lumbosacral spine, and specifically pelvic incidence (PI), has been implicated in the development of spine pathology, but generally ignored with regards to diseases of the hip. We aimed to determine if increased PI is correlated with higher rates of hip osteoarthritis (HOA). The effect of PI on the development of knee osteoarthritis (KOA) was used as a negative control.

The December 2015 Research Roundup360 looks at: Biomarkers in periprosthetic joint infection; HbA1c and complications in arthroplasty; Getting to the bottom of biofilms; Effective antibiosis for biofilms; Stem cells and avascular necrosis; Predicting LOS in total joint arthroplasty; Long-term antibiotics reduce recurrence in periprosthetic infection

Aims

The authors present the results of a cohort study of 60 adult patients presenting sequentially over a period of 15 years from 1997 to 2012 to our hospital for treatment of thoracic and/or lumbar vertebral burst fractures, but without neurological deficit.