We hypothesised that the removal of the subchondral bone plate (SCBP) for cemented acetabular component fixation in total hip arthroplasty (THA) offers advantages over retention by improving the cement-bone interface, without jeopardising implant stability. We have previously published two-year follow-up data of a randomised controlled trial (RCT), in which 50 patients with primary osteoarthritis were randomised to either retention or removal of the SCBP. The mean age of the retention group (n = 25, 13 males) was 70.0 years (sd 6.8). The mean age in the removal group (n = 25, 16 males) was 70.3 years (sd 7.9). Now we have followed up the patients at six (retention group, n = 21; removal group, n = 20) and ten years (retention group: n = 17, removal group: n = 18), administering clinical outcome questionnaires and radiostereometric analysis (RSA), and determining the presence of radiolucent lines (RLLs) on conventional radiographs. RSA demonstrated similar translation and rotation patterns up to six years. Between six and ten years, proximal acetabular component migration and changes of inclination were larger in the retention group, although the mean differences did not reach statistical significance. Differences in migration were driven by two patients in the SCBP retention group with extensive migration versus none in the SCBP removal group. The significant difference (p < 0.001) in the development of radiolucent lines in the retention group, previously observed at two years, increased even further during the course of follow-up (p < 0.001). While recognising SCBP removal is a more demanding technique, we conclude that, wherever possible, the SCBP should be removed to improve the cement–bone interface in order to maximise acetabular component stability and longevity.

Cite this article: Bone Joint J 2015;97-B:35–44.

The April 2013 Spine Roundup³⁶⁰ looks at: smuggling spinal implants; local bone graft and PLIF; predicting disability with slipped discs; mortality and spinal surgery; spondyloarthropathy; brachytherapy; and fibrin mesh and BMP.

Total knee replacement (TKR) smart tibial trials have load-bearing sensors which will show quantitative compartment pressure values and femoral-tibial tracking patterns. Without smart trials, surgeons rely on feel and visual estimation of imbalance to determine if the knee is optimally balanced. Corrective soft-tissue releases are performed with minimal feedback as to what and how much should be released. The smart tibial trials demonstrate graphically where and how much imbalance is present, so that incremental releases can be performed. The smart tibial trials now also incorporate accelerometers which demonstrate the axial alignment. This now allows the surgeon the option to perform a slight recut of the tibia or femur to provide soft-tissue balance without performing soft-tissue releases. Using a smart tibial trial to assist with soft-tissue releases or bone re-cuts, improved patient outcomes have been demonstrated at one year in a multicentre study of 135 patients (135 knees).

Cite this article: Bone Joint J 2014;96-B(11 Suppl A):78–83.

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.

The aim of this study was to define return to theatre (RTT) rates for elective hip and knee replacement (HR and KR), to describe the predictors and to show the variations in risk-adjusted rates by surgical team and hospital using national English hospital administrative data.

We examined information on 260 206 HRs and 315 249 KRs undertaken between April 2007 and March 2012. The 90-day RTT rates were 2.1% for HR and 1.8% for KR. Male gender, obesity, diabetes and several other comorbidities were associated with higher odds for both index procedures. For HR, hip resurfacing had half the odds of cement fixation (OR = 0.58, 95% confidence intervals (CI) 0.47 to 0.71). For KR, unicondylar KR had half the odds of total replacement (OR = 0.49, 95% CI 0.42 to 0.56), and younger ages had higher odds (OR = 2.23, 95% CI 1.65 to 3.01) for ages < 40 years compared with ages 60 to 69 years). There were more funnel plot outliers at three standard deviations than would be expected if variation occurred on a random basis.

Hierarchical modelling showed that three-quarters of the variation between surgeons for HR and over half the variation between surgeons for KR are not explained by the hospital they operated at or by available patient factors. We conclude that 90-day RTT rate may be a useful quality indicator for orthopaedics.

Cite this article: Bone Joint J 2014; 96-B:1663–8.

In a randomised controlled pragmatic trial we investigated whether local infiltration analgesia would result in earlier readiness for discharge from hospital after total knee replacement (TKR) than patient-controlled epidural analgesia (PCEA) plus femoral nerve block. A total of 45 patients with a mean age of 65 years (49 to 81) received a local infiltration with a peri-articular injection of bupivacaine, morphine and methylprednisolone, as well as adjuvant analgesics. In 45 PCEA+femoral nerve blockade patients with a mean age of 67 years (50 to 84), analgesia included a bupivacaine nerve block, bupivacaine/hydromorphone PCEA, and adjuvant analgesics. The mean time until ready for discharge was 3.2 days (1 to 14) in the local infiltration group and 3.2 days (1.8 to 7.0) in the PCEA+femoral nerve blockade group. The mean pain scores for patients receiving local infiltration were higher when walking (p = 0.0084), but there were no statistically significant differences at rest. The mean opioid consumption was higher in those receiving local infiltration.

The choice between these two analgesic pathways should not be made on the basis of time to discharge after surgery. Most secondary outcomes were similar, but PCEA+femoral nerve blockade patients had lower pain scores when walking and during continuous passive movement. If PCEA+femoral nerve blockade is not readily available, local infiltration provides similar length of stay and similar pain scores at rest following TKR.

Cite this article: Bone Joint J 2013;95-B:629–35.

Our objective was to examine the rate of revision and its predictive factors in patients undergoing total shoulder arthroplasty (TSA). We used prospectively collected data from the Mayo Clinic Total Joint Registry to examine five-, ten- and 20-year revision-free survival following TSA and the predictive factors. We examined patient characteristics (age, gender, body mass index, comorbidity), implant fixation (cemented versus uncemented), American Society of Anesthesiologists class and underlying diagnosis. Univariate and multivariable adjusted hazard rates were calculated using Cox regression analysis. A total of 2207 patients underwent 2588 TSAs. Their mean age was 65.0 years (19 to 91) and 1163 (53%) were women; osteoarthritis was the underlying diagnosis in 1640 shoulders (63%). In all, 212 TSAs (8.2%) were revised during the follow-up period. At five, ten and 20 years, survival rates were 94.2% (95% confidence interval (CI) 93.2 to 95.3), 90.2% (95% CI 88.7 to 91.7) and 81.4% (95% CI 78.4 to 84.5), respectively. In multivariable analyses men had a higher hazard ratio of revision of 1.72 (95% CI 1.28 to 2.31) (p < 0.01) compared with women, and those with rotator cuff disease had a hazard ratio of 4.71 (95% CI 2.09 to 10.59) (p < 0.001) compared with patients with rheumatoid arthritis. We concluded that male gender and rotator cuff disease are independent risk factors for revision after TSA. Future studies are needed to understand the biological rationale for these differences.

The October 2014 Oncology Roundup³⁶⁰ looks at: how best to reconstruct humeral tumours; not everything is better via the arthroscope; obesity and sarcoma; frozen autograft; en-bloc resection and metastatic disease; positive margins in soft-tissue injuries; lipomatous tumours explored; and what happens with recurrence of osteosarcoma.

The purpose of this study was to compare the amount of acetabular bone removed during hip resurfacing (HR) and cementless total hip replacement (THR), after controlling for the diameter of the patient’s native femoral head. Based on a power analysis, 64 consecutive patients (68 hips) undergoing HR or THR were prospectively enrolled in the study. The following data were recorded intra-operatively: the diameter of the native femoral head, the largest reamer used, the final size of the acetabular component, the size of the prosthetic femoral head and whether a decision was made to increase the size of the acetabular component in order to accommodate a larger prosthetic femoral head. Results were compared using two-sided, independent samples Student’s t-tests. A statistically significant difference was seen in the mean ratio of the size of the acetabular component to the diameter of the native femoral head (HR: 1.05 (sd 0.04) versus THR: 1.09 (sd 0.05); p <  0.001) and largest acetabular reamer used to the diameter of the native femoral head (HR: 1.03 (sd 0.04) versus THR: 1.09 (sd 0.05); p < 0.001). The ratios varied minimally when the groups were subdivided by gender, age and obesity. The decision to increase the size of the acetabular component to accommodate a larger femoral head occurred more often in the THR group (27% versus 9%). Despite the emphasis on avoiding damage to the femoral neck during HR, the ratio of the size of the acetabular component to the diameter of the native femoral head was larger in cementless THR than in HR.

The strain on clinic and surgeon resources resulting from a rise in demand for total knee replacement (TKR) requires reconsideration of when and how often patients need to be seen for follow-up. Surgeons will otherwise require increased paramedical staff or need to limit the number of TKRs they undertake. We reviewed the outcome data of 16 414 primary TKRs undertaken at our centre to determine the time to re-operation for any reason and for specific failure mechanisms. Peak risk years for failure were determined by comparing the conditional probability of failure, the number of failures divided by the total number of TKRs cases, for each year. The median times to failure for the most common failure mechanisms were 4.9 years (interquartile range (IQR) 1.7 to 10.7) for femoral and tibial loosening, 1.9 years (IQR 0.8 to 3.9) for infection, 3.1 years (IQR 1.6 to 5.5) for tibial collapse and 5.6 years (IQR 3.4 to 9.3) for instability. The median time to failure for all revisions was 3.3 years (IQR 1.2 to 8.5), with an overall revision rate of 1.7% (n = 282). Results from our patient population suggest that patients be seen for follow-up at six months, one year, three years, eight years, 12 years, and every five years thereafter. Patients with higher pain in the early post-operative period or high body mass index (≥ 41 kg/m²) should be monitored more closely.

Cite this article: Bone Joint J 2013;95-B:1484–9.

In this prospective study a total of 80 consecutive Chinese patients with Crowe type I or II developmental dysplasia of the hip were randomly assigned for hip resurfacing arthroplasty (HRA) or total hip replacement (THR).

Three patients assigned to HRA were converted to THR, and three HRA patients and two THR patients were lost to follow-up. This left a total of 34 patients (37 hips) who underwent HRA and 38 (39 hips) who underwent THR. The mean follow-up was 59.4 months (52 to 70) in the HRA group and 60.6 months (50 to 72) in the THR group. There was no failure of the prosthesis in either group. Flexion of the hip was significantly better after HRA, but there was no difference in the mean post-operative Harris hip scores between the groups. The mean size of the acetabular component in the HRA group was significantly larger than in the THR group (49.5 mm vs 46.1 mm, p = 0.001). There was no difference in the mean abduction angle of the acetabular component between the two groups.

Although the patients in this series had risk factors for failure after HRA, such as low body weight, small femoral heads and dysplasia, the clinical results of resurfacing in those with Crowe type I or II hip dysplasia were satisfactory. Patients in the HRA group had a better range of movement, although neck-cup impingement was observed. However, more acetabular bone was sacrificed in HRA patients, and it is unclear whether this will have an adverse effect in the long term.

Early and accurate prediction of hospital length-of-stay (LOS) in patients undergoing knee replacement is important for economic and operational reasons. Few studies have systematically developed a multivariable model to predict LOS. We performed a retrospective cohort study of 1609 patients aged ≥ 50 years who underwent elective, primary total or unicompartmental knee replacements. Pre-operative candidate predictors included patient demographics, knee function, self-reported measures, surgical factors and discharge plans. In order to develop the model, multivariable regression with bootstrap internal validation was used. The median LOS for the sample was four days (interquartile range 4 to 5). Statistically significant predictors of longer stay included older age, greater number of comorbidities, less knee flexion range of movement, frequent feelings of being down and depressed, greater walking aid support required, total (versus unicompartmental) knee replacement, bilateral surgery, low-volume surgeon, absence of carer at home, and expectation to receive step-down care. For ease of use, these ten variables were used to construct a nomogram-based prediction model which showed adequate predictive accuracy (optimism-corrected R² = 0.32) and calibration. If externally validated, a prediction model using easily and routinely obtained pre-operative measures may be used to predict absolute LOS in patients following knee replacement and help to better manage these patients.

Cite this article: Bone Joint J 2013;95-B:1490–6.

We conducted a retrospective study to assess the prevalence of adverse reactions to metal debris (ARMD) in patients operated on at our institution with metal-on-metal (MoM) total hip replacements with 36 mm heads using a Pinnacle acetabular shell. A total of 326 patients (150 males, 175 hips; 176 females, 203 hips) with a mean age of 62.7 years (28 to 85) and mean follow-up of 7.5 years (0.1 to 10.8) participating in our in-depth modern MoM follow-up programme were included in the study, which involved recording whole blood cobalt and chromium ion measurements, Oxford hip scores (OHS) and plain radiographs of the hip and targeted cross-sectional imaging. Elevated blood metal ion levels (> 5 parts per billion) were seen in 32 (16.1%) of the 199 patients who underwent unilateral replacement. At 23 months after the start of our modern MoM follow-up programme, 29 new cases of ARMD had been revealed. Hence, the nine-year survival of this cohort declined from 96% (95% CI 95 to 98) with the old surveillance routine to 86% (95% CI 82 to 90) following the new protocol. Although ARMD may not be as common in 36 mm MoM THRs as in those with larger heads, these results support the Medicines and Healthcare Products Regulatory Agency guidelines on regular reviews and further investigations, and emphasise the need for specific a follow-up programme for patients with MoM THRs.

Cite this article: Bone Joint J 2014; 96-B:1610–17.

Despite the worldwide usage of the cemented Contemporary acetabular component (Stryker), no published data are available regarding its use in patients aged < 50 years. We undertook a mid- to long-term follow-up study, including all consecutive patients aged < 50 years who underwent a primary total hip replacement using the Contemporary acetabular component with the Exeter cemented stem between January 1999 and January 2006. There were 152 hips in 126 patients, 61 men and 65 women, mean age at surgery 37.6 years (16 to 49 yrs). One patient was lost to follow-up.

Mean clinical follow-up of all implants was 7.6 years (0.9 to 12.0). All clinical questionnaire scores, including Harris hip score, Oxford hip score and several visual analogue scales, were found to have improved. The eight year survivorship of all acetabular components for the endpoints revision for any reason or revision for aseptic loosening was 94.4% (95% confidence interval (CI) 89.2 to 97.2) and 96.4% (95% CI 91.6 to 98.5), respectively. Radiological follow-up was complete for 146 implants. The eight year survival for the endpoint radiological loosening was 93.1% (95% CI 86.2 to 96.6). Three surviving implants were considered radiologically loose but were asymptomatic. The presence of acetabular osteolysis (n = 17, 11.8%) and radiolucent lines (n = 20, 13.9%) in the 144 surviving cups indicates a need for continued observation in the second decade of follow-up in order to observe their influence on long-term survival.

The clinical and radiological data resulting in a ten-year survival rate > 90% in young patients support the use of the Contemporary acetabular component in this specific patient group.

Cite this article: Bone Joint J 2013;95-B:1617–25.

We evaluated the clinical results and complications after extra-articular resection of the distal femur and/or proximal tibia and reconstruction with a tumour endoprosthesis (MUTARS) in 59 patients (mean age 33 years (11 to 74)) with malignant bone or soft-tissue tumours. According to a Kaplan–Meier analysis, limb survival was 76% (95% confidence interval (CI) 64.1 to 88.5) after a mean follow-up of 4.7 years (one month to 17 years). Peri-prosthetic infection was the most common indication for subsequent amputation (eight patients). Survival of the prosthesis without revision was 48% (95% CI 34.8 to 62.0) at two years and 25% (95% CI 11.1 to 39.9) at five years post-operatively. Failure of the prosthesis was due to deep infection in 22 patients (37%), aseptic loosening in ten patients (17%), and peri-prosthetic fracture in six patients (10%). Wear of the bearings made a minor revision necessary in 12 patients (20%). The mean Musculoskeletal Tumor Society score was 23 (10 to 29). An extensor lag > 10° was noted in ten patients (17%).

These results suggest that limb salvage after extra-articular resection with a tumour prosthesis can achieve good functional results in most patients, although the rates of complications and subsequent amputation are higher than in patients treated with intra-articular resection.

Cite this article: Bone Joint J 2013;95-B:1425–31.

The aim of this study was to define the incidence of venous thromboembolism (VTE) and risk factors for the development of deep-vein thrombosis (DVT) after the resection of a musculoskeletal tumour. A total of 94 patients who underwent resection of a musculoskeletal tumour between January 2003 and December 2005 were prospectively studied. There were 42 men and 52 women with a mean age of 54.4 years (18 to 86). All patients wore intermittent pneumatic compression devices and graduated compression stockings. Ultrasound examination of the lower limbs was conducted to screen for DVT between the fifth and ninth post-operative days.

DVT was detected in 21 patients (22%). Of these, two were symptomatic (2%). One patient (1%) had a fatal pulmonary embolism. Patients aged ≥ 70 years had an increased risk of DVT (p = 0.004).

The overall incidence of DVT (both symptomatic and asymptomatic) after resection of a musculoskeletal tumour with mechanical prophylaxis was high. It seems that both mechanical and anticoagulant prophylaxis is needed to prevent VTE in patients who have undergone the resection of a musculoskeletal tumour.

Cite this article: Bone Joint J 2013;95-B:1280–4.

The August 2014 Shoulder & Elbow Roundup³⁶⁰ looks at: Myofibroblasts perhaps not implicated in post-traumatic elbow stiffness; olecranon tip biomechanically sound for coranoid reconstruction; obesity and elbow replacement don’t mix; single column plating successful for extra-articular distal humeral fractures; satisfaction not predictable in frozen shoulder; tenodesis and repair both acceptable in Grade II SLAP tears; glenoid bone grafting is effective and glenohumeral articular lesions best seen with an arthroscope.

Pre-operative variables are increasingly being used to determine eligibility for total knee replacement (TKR). This study was undertaken to evaluate the relationships, interactions and predictive capacity of variables available pre- and post-operatively on patient satisfaction following TKR. Using nationally collected patient reported outcome measures and data from the National Joint Registry for England and Wales, we identified 22 798 patients who underwent TKR for osteoarthritis between August 2008 and September 2010. The ability of specific covariates to predict satisfaction was assessed using ordinal logistic regression and structural equational modelling. Only 4959 (22%) of 22 278 patients rated the results of their TKR as ‘excellent’, despite the majority (71%, n = 15 882) perceiving their knee symptoms to be much improved. The strongest predictors of satisfaction were post-operative variables. Satisfaction was significantly and positively related to the perception of symptom improvement (operative success) and the post-operative EuroQol-5D score. While also significant within the models pre-operative variables were less important and had a minimal influence upon post-operative satisfaction. The most robust predictions of satisfaction occurred only when both pre- and post-operative variables were considered together. These findings question the appropriateness of restricting access to care based on arbitrary pre-operative thresholds as these factors have little bearing on post-operative satisfaction.

Cite this article: Bone Joint J 2013;95-B:1359–65.

The aim of this study was to identify the incidence of post-operative symptomatic deep-vein thrombosis (DVT), as well as the risk factors for and location of DVT, in 665 patients (701 ankles) who underwent primary total ankle replacement. All patients received low-molecular-weight heparin prophylaxis. A total of 26 patients (3.9%, 26 ankles) had a symptomatic DVT, diagnosed by experienced radiologists using colour Doppler ultrasound. Most thrombi (22 patients, 84.6%) were localised distally in the operated limb. Using a logistic multiple regression model we identified obesity, a previous venous thromboembolic event and the absence of full post-operative weight-bearing as independent risk factors for developing a symptomatic DVT.

The incidence of symptomatic DVT after total ankle replacement and use of low-molecular-weight heparin is comparable with that in patients undergoing total knee or hip replacement.

In this prospective study we studied the effect of the inclination angle of the acetabular component on polyethylene wear and component migration in cemented acetabular sockets using radiostereometric analysis.

A total of 120 patients received either a cemented Reflection All-Poly ultra-high-molecular-weight polyethylene or a cemented Reflection All-Poly highly cross-linked polyethylene acetabular component, combined with either cobalt–chrome or Oxinium femoral heads. Femoral head penetration and migration of the acetabular component were assessed with repeated radiostereometric analysis for two years. The inclination angle was measured on a standard post-operative anteroposterior pelvic radiograph. Linear regression analysis was used to determine the relationship between the inclination angle and femoral head penetration and migration of the acetabular component.

We found no relationship between the inclination angle and penetration of the femoral head at two years’ follow-up (p = 0.9). Similarly, our data failed to reveal any statistically significant correlation between inclination angle and migration of these cemented acetabular components (p = 0.07 to p = 0.9).