The most frequent cause of failure after total hip replacement in all reported arthroplasty registries is peri-prosthetic osteolysis. Osteolysis is an active biological process initiated in response to wear debris. The eventual response to this process is the activation of macrophages and loss of bone.

Activation of macrophages initiates a complex biological cascade resulting in the final common pathway of an increase in osteolytic activity. The biological initiators, mechanisms for and regulation of this process are beginning to be understood. This article explores current concepts in the causes of, and underlying biological mechanism resulting in peri-prosthetic osteolysis, reviewing the current basic science and clinical literature surrounding the topic.

Alumina–alumina bearings are among the most resistant to wear in total hip replacement. Examination of their surfaces is one way of comparing damage caused by wear of hip joints simulated in vitro to that seen in explanted bearings. The aim of this study was to determine whether second-generation ceramic bearings exhibited a better pattern of wear than those reported in the literature for first-generation bearings. We considered both macro- and microscopic findings.

We found that long-term alumina wear in association with a loose acetabular component could be categorised into three groups. Of 20 specimens, four had ‘low wear’, eight ‘crescent wear’ and eight ‘severe wear’, which was characterised by a change in the physical shape of the bearing and a loss of volume. This suggests that the wear in alumina–alumina bearings in association with a loose acetabular component may be variable in pattern, and may explain, in part, why the wear of a ceramic head in vivo may be greater than that seen after in vitro testing.

An 81-year-old woman presented with a fracture in the left femur. She had well-fixed bilateral hip replacements and had received long-term bisphosphonate treatment. Prolonged bisphosphonate use has been recently linked with atypical subtrochanteric and diaphyseal femoral fractures. While the current definition of an atypical fracture of the femur excludes peri-prosthetic fractures, this case suggests that they do occur and should be considered in patients with severe osteopenia. Union of the fracture followed cessation of bisphosphonates and treatment with teriparatide. Thus, this case calls into question whether prophylactic intramedullary nailing is sufficient alone to treat early or completed atypical femoral fractures.

We report the long-term results of revision total hip replacement using femoral impaction allografting with both uncemented and cemented Freeman femoral components. A standard design of component was used in both groups, with additional proximal hydroxyapatite coating in the uncemented group. A total of 33 hips in 30 patients received an uncemented component and 31 hips in 30 patients a cemented component. The mean follow-up was 9.8 years (2 to 17) in the uncemented group and 6.2 years (1 to 11) in the cemented group. Revision procedures (for all causes) were required in four patients (four hips) in the uncemented group and in five patients (five hips) in the cemented group. Harris hip scores improved significantly in both groups and were maintained independently of the extent of any migration of the femoral component within the graft or graft–cement mantle.

We report the incidence and intensity of persistent pain in patients with an otherwise uncomplicated total ankle replacement (TAR). Arthroscopic debridement was performed in selected cases and the clinical outcome was analysed.

Among 120 uncomplicated TARs, there was persistent pain with a mean visual analogue scale (VAS) of 2.7 (0 to 8). The intensity of pain decreased in 115 ankles (95.8%). Exercise or walking for more than 30 minutes was the most common aggravating factor (62 ankles, 68.1%). The character of the pain was most commonly described as dull (50 ankles, 54.9%) and located on the medial aspect of the joint (43 ankles, 47.3%).

A total of seven ankles (5.8%) underwent subsequent arthroscopy. These patients had local symptoms and a VAS for pain ≥ 7 on exertion. Impingement with fibrosis and synovitis was confirmed. After debridement, the median VAS decreased from 7 to 3 and six patients were satisfied. The median VAS for pain and the American Orthopaedic Foot and Ankle Society score of the ankles after debridement was similar to that of the uncomplicated TARs (p = 0.496 and p = 0.066, respectively).

Although TAR reduces the intensity of pain, residual pain is not infrequent even in otherwise uncomplicated TARs and soft-tissue impingement is the possible cause.

Cite this article: Bone Joint J 2013;95-B:378–83.

In the UK we have many surgeon inventors – surgeons who innovate and create new ways of doing things, who invent operations, who design new instruments to facilitate surgery or design new implants for using in patients. However truly successful surgeon inventors are a rare breed and they need to develop additional knowledge and skills during their career in order to push forward their devices and innovations. This article reviews my own experiences as a surgeon inventor and the highs and lows over the whole of my surgical career.

We performed a case–control study to compare the rates of further surgery, revision and complications, operating time and survival in patients who were treated with either an uncemented hydroxyapatite-coated Corail bipolar femoral stem or a cemented Exeter stem for a displaced intracapsular fracture of the hip. The mean age of the patients in the uncemented group was 82.5 years (53 to 97) and in the cemented group was 82.7 years (51 to 99) We used propensity score matching, adjusting for age, gender and the presence or absence of dementia and comorbidities, to produce a matched cohort receiving an Exeter stem (n = 69) with which to compare the outcome of patients receiving a Corail stem (n = 69). The Corail had a significantly lower all-cause rate of further surgery (p = 0.016; odds ratio (OR) 0.18, 95% CI 0.04 to 0.84) and number of hips undergoing major further surgery (p = 0.029; OR 0.13, 95% CI 0.01 to 1.09). The mean operating time was significantly less for the Corail group than for the cemented Exeter group (59 min [12 to 136] vs 70 min [40 to 175], p = 0.001). The Corail group also had a lower risk of a peri-prosthetic fracture (p = 0.042; OR 0.19, 95% CI 0.01 to 1.42) . There was no difference in the mortality rate between the groups. There were significantly fewer complications in the uncemented group, suggesting that the use of this stem would result in a decreased rate of morbidity in these frail patients. Whether this relates to an improved functional outcome remains unknown.

Cite this article: Bone Joint J 2014;96-B:299–305.

Peri-prosthetic femoral fracture after total hip replacement (THR) is associated with a poor outcome and high mortality. However, little is known about its long-term incidence after uncemented THR.

We retrospectively reviewed a consecutive series of 326 patients (354 hips) who had received a CLS Spotorno replacement with an uncemented, straight, collarless tapered titanium stem between January 1985 and December 1989. The mean follow-up was 17 years (15 to 20). The occurrence of peri-prosthetic femoral fracture during follow-up was noted. Kaplan-Meier survival analysis was used to estimate the cumulative incidence of fracture.

At the last follow-up, 86 patients (89 hips) had died and eight patients (eight hips) had been lost to follow-up. A total of 14 fractures in 14 patients had occurred. In ten hips, the femoral component had to be revised and in four the fracture was treated by open reduction and internal fixation. The cumulative incidence of peri-prosthetic femoral fracture was 1.6% (95% confidence interval 0.7 to 3.8) at ten years and 4.5% (95% confidence interval 2.6 to 8.0) at 17 years after the primary THR. There was no association between the occurrence of fracture and gender or age at the time of the primary replacement.

Our findings indicate that peri-prosthetic femoral fracture is a significant mode of failure in the long term after the insertion of an uncemented CLS Spotorno stem. Revision rates for this fracture rise in the second decade. Further research is required to investigate the risk factors involved in the occurrence of late peri-prosthetic femoral fracture after the implantation of any uncemented stem, and to assess possible methods of prevention.

There has been a substantial increase in the number of hip and knee prostheses implanted in recent years, with a consequent increase in the number of revisions required. Total femur replacement (TFR) following destruction of the entire femur, usually after several previous revision operations, is a rare procedure but is the only way of avoiding amputation. Intramedullary femur replacement (IFR) with preservation of the femoral diaphysis is a modification of TFR. Between 1999 and 2010, 27 patients with non-oncological conditions underwent surgery in our department with either IFR (n = 15) or TFR (n = 12) and were included in this study retrospectively. The aim of the study was to assess the indications, complications and outcomes of IFR and TFR in revision cases. The mean follow-up period was 31.3 months (6 to 90). Complications developed in 37% of cases, 33% in the IFR group and 4% in the TFR group. Despite a trend towards a slightly better functional outcome compared with TFR, the indication for intramedullary femur replacement should be established on a very strict basis in view of the procedure’s much higher complication rate.

The February 2013 Children’s orthopaedics Roundup³⁶⁰ looks at: the human genome; new RNA; cells, matrix and gene enhancement; the histology of x-rays; THR and VTE in the Danish population; potential therapeutic targets for GCT; optimising vancomycin elution from cement; and how much sleep is enough.

The February 2014 Knee Roundup³⁶⁰ looks at: whether sham surgery is as good as arthroscopic meniscectomy; distraction in knee osteoarthritis; whether trans-tibial tunnel placement increases the risk of graft failure in ACL surgery; whether joint replacements prevent cardiac events; the size of the pulmonary embolism problem; tranexamic acid and knee replacement haemostasis; matching the demand for knee replacement and follow-up; predicting the length of stay after knee replacement; and popliteal artery injury in TKR.

Using data from the Norwegian Hip Fracture Register, 8639 cemented and 2477 uncemented primary hemiarthroplasties for displaced fractures of the femoral neck in patients aged > 70 years were included in a prospective observational study. A total of 218 re-operations were performed after cemented and 128 after uncemented procedures. Survival of the hemiarthroplasties was calculated using the Kaplan-Meier method and hazard rate ratios (HRR) for revision were calculated using Cox regression analyses. At five years the implant survival was 97% (95% confidence interval (CI) 97 to 97) for cemented and 91% (95% CI 87 to 94) for uncemented hemiarthroplasties. Uncemented hemiarthroplasties had a 2.1 times increased risk of revision compared with cemented prostheses (95% confidence interval 1.7 to 2.6, p < 0.001). The increased risk was mainly caused by revisions for peri-prosthetic fracture (HRR = 17), aseptic loosening (HRR = 17), haematoma formation (HRR = 5.3), superficial infection (HRR = 4.6) and dislocation (HRR = 1.8). More intra-operative complications, including intra-operative death, were reported for the cemented hemiarthroplasties. However, in a time-dependent analysis, the HRR for re-operation in both groups increased as follow-up increased.

This study showed that the risk for revision was higher for uncemented than for cemented hemiarthroplasties.

If a surgeon is faced with altered lesser trochanter anatomy when revising the femoral component in revision total hip replacement, a peri-prosthetic fracture, or Paprosky type IIIb or type IV femoral bone loss, a modular tapered stem offers the advantages of accurately controlling femoral version and length. The splines of the taper allow rotational control, and improve the fit in femoral canals with diaphyseal bone loss. In general, two centimetres of diaphyseal contact is all that is needed to gain stability with modular tapered stems. By allowing the proximal body trial to rotate on a well-fixed distal segment during trial reduction, appropriate anteversion can be obtained in order to improve intra-operative stability, and decrease the dislocation risk. However, modular stems should not be used for all femoral revisions, as implant fracture and corrosion at modular junctions can still occur.

Cite this article: Bone Joint J 2013;95-B, Supple A:95–7.

Femoral revision after cemented total hip replacement (THR) might include technical difficulties, following essential cement removal, which might lead to further loss of bone and consequently inadequate fixation of the subsequent revision stem.

Femoral impaction allografting has been widely used in revision surgery for the acetabulum, and subsequently for the femur. In combination with a primary cemented stem, impaction grafting allows for femoral bone restoration through incorporation and remodelling of the impacted morsellized bone graft by the host skeleton. Cavitary bone defects affecting meta-physis and diaphysis leading to a wide femoral shaft, are ideal indications for this technique. Cancellous allograft bone chips of 1 mm to 2 mm size are used, and tapered into the canal with rods of increasing diameters. To impact the bone chips into the femoral canal a prosthesis dummy of the same dimensions of the definitive cemented stem is driven into the femur to ensure that the chips are very firmly impacted. Finally, a standard stem is cemented into the neo-medullary canal using bone cement.

To date several studies have shown favourable results with this technique, with some excellent long-term results reported in independent clinical centres worldwide.

Cite this article: Bone Joint J 2013;95-B, Supple A:92–4.

Metal-on-metal hip arthroplasty gained significant favor in the first decade of the millennium. However, the past several years have seen increasing reports of failure, pseudotumor and other adverse reactions. This study presents the results of a single center’s 15-year experience with metal-on-metal total hip arthroplasty as strong evidence that metal-on-metal is going, going, gone.

The rate of peri-prosthetic infection following total joint replacement continues to rise, and attempts to curb this trend have included the use of antibiotic-loaded bone cement at the time of primary surgery. We have investigated the clinical- and cost-effectiveness of the use of antibiotic-loaded cement for primary total knee replacement (TKR) by comparing the rate of infection in 3048 TKRs performed without loaded cement over a three-year period versus the incidence of infection after 4830 TKRs performed with tobramycin-loaded cement over a later period of time of a similar duration. In order to adjust for confounding factors, the rate of infection in 3347 and 4702 uncemented total hip replacements (THR) performed during the same time periods, respectively, was also examined. There were no significant differences in the characteristics of the patients in the different cohorts.

The absolute rate of infection increased when antibiotic-loaded cement was used in TKR. However, this rate of increase was less than the rate of increase in infection following uncemented THR during the same period. If the rise in the rate of infection observed in THR were extrapolated to the TKR cohort, 18 additional cases of infection would have been expected to occur in the cohort receiving antibiotic-loaded cement, compared with the number observed. Depending on the type of antibiotic-loaded cement that is used, its cost in all primary TKRs ranges between USD $2112.72 and USD $112 606.67 per case of infection that is prevented.

Cite this article: Bone Joint J 2014;96-B:65–9.

We reviewed the long-term clinical and radiological results of 63 uncemented Low Contact Stress (LCS) total knee replacements (TKRs) in 47 patients with rheumatoid arthritis. The mean age of the patients at the time of surgery was 69 years (53 to 81). At a mean follow-up of 22 years (20 to 25), 12 patients were alive (17 TKRs), 27 had died (36 TKRs), and eight (ten TKRs) were lost to follow-up.

Revision was necessary in seven patients (seven TKRs, 11.1%) at a mean of 12.1 years (0 to 19) after surgery. In the surviving ten patients who had not undergone revision (15 TKRs), the mean Oxford knee score was 30.2 (16 to 41) at a mean follow-up of 19.5 years (15 to 24.7) and mean active flexion was 105° (90° to 150°). The survival rate was 88.9% at 20 years (56 of 63) and the Kaplan–Meier survival estimate, without revision, was 80.2% (95% confidence interval 37 to 100) at 25 years.

Cite this article: Bone Joint J 2013;95-B:1497–9.

Treatment of an infected total elbow replacement (TER) is often successful in eradicating or suppressing the infection. However, the extensor mechanism may be compromised by both the infection and the surgery. The goal of this study was to assess triceps function in patients treated for deep infection complicating a TER. Between 1976 and 2007 a total of 217 TERs in 207 patients were treated for infection of a TER at our institution. Superficial infections and those that underwent resection arthroplasty were excluded, leaving 93 TERs. Triceps function was assessed by examination and a questionnaire. Outcome was measured using the Mayo Elbow Performance Score (MEPS).

Triceps weakness was identified in 51 TERs (49 patients, 55%). At a mean follow-up of five years (0.8 to 34), the extensor mechanism was intact in 13 patients, with the remaining 38 having bone or soft-tissue loss. The mean MEPS was 70 points (5 to 100), with a mean functional score of 18 (0 to 25) of a possible 25 points.

Infection following TER can often be eradicated; however, triceps weakness occurs in more than half of the patients and may represent a major functional problem.

Cite this article: Bone Joint J 2014;96-B:82–7.

We report the clinical and radiological outcome of total ankle replacement performed in conjunction with hindfoot fusion or in isolation. Between May 2003 and June 2008, 60 ankles were treated with total ankle replacement with either subtalar or triple fusion, and the results were compared with a control group of 288 ankles treated with total ankle replacement alone.

After the mean follow-up of 39.5 months (12 to 73), the ankles with hindfoot fusion showed significant improvement in the mean visual analogue score for pain (p < 0.001), the mean American Orthopaedic Foot and Ankle Society score (p < 0.001), and the mean of a modified version of this score (p < 0.001). The mean visual analogue pain score (p = 0.304) and mean modified American Orthopaedic Foot and Ankle Society score (p = 0.119) were not significantly different between the hindfoot fusion and the control groups. However, the hindfoot fusion group had a significantly lower mean range of movement (p = 0.009) and a higher rate of posterior focal osteolysis (p = 0.04). Both groups showed various complications (p = 0.131) and failure occurring at a similar rate (p = 0.685).

Subtalar or triple fusion is feasible and has minimal adverse effects on ankles treated with total ankle replacement up to midterm follow-up. The clinical outcome of total ankle replacement when combined with hindfoot fusion is comparable to that of ankle replacement alone. Thus, hindfoot fusion should be performed in conjunction with total ankle replacement when indicated.