Introduction

Unstable ankle fractures are routinely managed operatively. Due to soft-tissue and implant related complications, there has been recent literature reporting on the non-operative management of well-reduced medial malleolus fractures following fibular stabilisation, but with limited evidence supporting routine application. This trial assessed the superiority of internal fixation of well-reduced (displacement ≤2mm) medial malleolus fractures compared with non-fixation following fibular stabilisation.

Introduction

The regionalisation of major trauma in the UK has significantly improved outcomes for patients with severe, lower limb injuries. Chronic pain after complex lower limb injuries is well documented, but seems to remain a problem despite better clinical and radiological outcomes. We hypothesised that pain was mediated through the saphenous nerve, especially as most tibial injuries affected the soft tissues medially. As a proof of concept, we undertook adductor canal blocks to understand pain aetiology.

This single-centre prospective randomised trial aimed to assess the superiority of operative fixation compared with non-operative management for adults with an isolated, closed humeral shaft fracture.

70 patients were randomly allocated to either open reduction and internal fixation (51%, n=36/70) or functional bracing (49%, n=34/70). 7 patients did not receive their assigned treatment (operative n=5/32, non-operative n=2/32); results were analysed based upon intention-to-treat. The primary outcome measure was the DASH score at 3 months. Secondary outcomes included treatment complications, union/nonunion, shoulder/elbow range of motion, pain and health-related quality of life (HRQoL).

At 3 months, 66 patients (94%) were available for follow-up; the mean DASH favoured surgery (operative 24.5, non-operative 39.4; p=0.006) and the difference (14.9 points) exceeded the MCID. Surgery was also associated with a superior DASH at 6wks (operative 38.4, non-operative 53.1; p=0.005) but not at 6 months or 1yr. Brace-related dermatitis affected 7 patients (operative 3%, non-operative 18%; OR 7.8, p=0.049) but there were no differences in other complications. 8 patients (11%) developed a nonunion (operative 6%, non-operative 18%; OR 3.8, p=0.140). Surgery was associated with superior early shoulder/elbow range of motion, and pain, EuroQol and SF-12 Mental Component Summary scores. There were no other differences in outcomes between groups.

Surgery confers early advantages over bracing, in terms of upper limb function, shoulder/elbow range of motion, pain and HRQoL. However, these benefits should be considered in the context of potential operative risks and the absence of any difference in patient-reported outcomes at 1yr.

The aim of this study was to determine the floor and ceiling effects for both the QuickDASH and PRWE following a fracture of the distal radius. Secondary aims were to determine the degree to which patients with a floor or ceiling effect felt that their wrist was ‘normal’, and if there were patient factors associated with achieving a floor or ceiling effect.

A retrospective cohort study of patients sustaining a distal radius fracture and managed at the study centre during a single year was undertaken. Outcome measures included the QuickDASH, the PRWE, EuroQol-5 Dimension-3 Levels (EQ-5D-3L), and the normal wrist score.

There were 526 patients with a mean age of 65yrs (20–95) and 421 (77%) were female. Most patients were managed non-operatively (73%, n=385). The mean follow-up was 4.8yrs (4.3–5.5). A ceiling effect was observed for both the QuickDASH (22.3%) and PRWE (28.5%). When defined to be within the minimum clinical important difference of the best available score, the ceiling effect increased to 62.8% for the QuickDASH and 60% for the PRWE. Patients that achieved a ceiling score for the QuickDASH and PRWE subjectively felt their wrist was only 91% and 92% normal, respectively. On logistic regression analysis, a dominant hand injury and better health-related quality of life were the common factors associated with achieving a ceiling score for both the QuickDASH and PRWE (all p<0.05).

The QuickDASH and PRWE demonstrate ceiling effects when used to assess the outcome of fractures of the distal radius. Patients achieving ceiling scores did not consider their wrist to be ‘normal’. Future patient-reported outcome assessment tools for fractures of the distal radius should aim to limit the ceiling effect, especially for individuals or groups that are more likely to achieve a ceiling score.

The aim was to predict the number and incidence of distal radius fractures in Scotland over the next two decades according to age group, categorised into under 65yrs(<65) and 65yrs and older (≥65), and estimate the potential increased operative burden of this.

The number of distal radius fracture in Scotland was isolated from the Global Burden of Disease database and this was used, in addition to historic population data and population estimates, to create a multivariable model allowing incorporation of age group, sex and time. A Negative Binomial distribution was used to predict incidence in 2030 and 2040 and calculate projected number of fractures according to the population at risk. A 20.4% operative intervention rate was assumed in the ≥65 group (local data).

In terms of number of fractures, there was a projected 61% rise in the ≥65 group with an overall increase of 2099 fractures per year from 3417 in 2020 (95% confidence interval (CI) 2960 – 3463) to 5516 in 2040 (95% CI 4155–5675). This was associated with 428 additional operative interventions per year for those ≥65yrs. The projected increase between 2020 and 2040 was similar in both sexes (60% in females, 63% in males), however the absolute increase in fracture number was higher in females (2256 in 2020 [95% CI 1954–2287] to 3620 in 2040 [95% CI 2727–3721]) compared to males (1160 [95% CI 1005–1176] to 1895 [95% CI 1427–1950]). There was a 4% projected fall in the number of fractures in those <65.

Incidence of distal radius fractures is expected to considerably increase over the next two decades due to a projected increase in the number of fractures in the elderly. This has implications for the associated morbidity and healthcare resource use.

This systematic review and meta-analysis aimed to compare the outcome of operative and non-operative management in adults with distal radius fractures, with an additional elderly subgroup analysis. The main outcome was 12-month PRWE score. Secondary outcomes included DASH score, grip strength, complications and radiographic parameters.

Randomised controlled trials of patients aged ≥18yrs with a dorsally displaced distal radius fractures were included. Studies compared operative intervention with non-operative management. Operative management included open reduction and internal fixation, Kirschner-wiring or external fixation. Non-operative management was cast/splint immobilisation with/without closed reduction. Version 2 of the Cochrane risk-of-bias tool was used.

After screening 1258 studies, 16 trials with 1947 patients (mean age 66yrs, 76% female) were included in the meta-analysis. Eight studies reported PRWE score and there was no clinically significant difference at 12 weeks (MD 0.16, 95% confidence interval [CI] −0.75 to 1.07, p=0.73) or 12 months (mean difference [MD] 3.30, 95% CI −5.66 to −0.94, p=0.006). Four studies reported on scores in the elderly and there was no clinically significant difference at 12 weeks (MD 0.59, 95% CI −0.35 to 1.53, p=0.22) or 12 months (MD 2.60, 95% CI −5.51 to 0.30, p=0.08). There was a no clinically significant difference in DASH score at 12 weeks (MD 10.18, 95% CI −14.98 to −5.38, p<0.0001) or 12 months (MD 3.49, 95% CI −5.69 to −1.29, p=0.002). Two studies featured only elderly patients, with no clinically important difference at 12 weeks (MD 7.07, 95% CI −11.77 to −2.37, p=0.003) or 12 months (MD 3.32, 95% CI −7.03 to 0.38, p=0.08).

There was no clinically significant difference in patient-reported outcome according to PRWE or DASH at either timepoint in the adult group as a whole or in the elderly subgroup.

Aims

This prospective study reports longitudinal, within-patient, patient-reported outcome measures (PROMs) over a 15-year period following cemented single radius total knee arthroplasty (TKA). Secondary aims included reporting PROMs trajectory, 15-year implant survival, and patient attrition from follow-up.

To develop a reliable and effective radiological score to assess the healing of isolated ulnar shaft fractures (IUSF), the Radiographic Union Score for Ulna fractures (RUSU).

Initially, 20 patients with radiographs six weeks following a non-operatively managed ulnar shaft fracture were selected and scored by three blinded observers. After intraclass correlation (ICC) analysis, a second group of 54 patients with radiographs six weeks after injury (18 who developed a nonunion and 36 who united) were scored by the same observers.

In the initial study, interobserver and intraobserver ICC were 0.89 and 0.93, respectively. In the validation study the interobserver ICC was 0.85. The median score for patients who united was significantly higher than those who developed a nonunion (11 vs 7, p<0.001). A ROC curve demonstrated that a RUSU ≤8 had a sensitivity of 88.9% and specificity of 86.1% in identifying patients at risk of nonunion. Patients with a RUSU ≤8 (n = 21) were more likely to develop a nonunion (n = 16/21) than those with a RUSU ≥9 (n = 2/33; OR 49.6, 95% CI 8.6–284.7). Based on a PPV of 76%, if all patients with a RUSU ≤8 underwent fixation at 6-weeks, the number of procedures needed to avoid one nonunion would be 1.3.

The RUSU shows good interobserver and intraobserver reliability and is effective in identifying patients at risk of nonunion six weeks after fracture. This tool requires external validation but may enhance the management of patients with isolated ulnar shaft fractures.

The primary aim was to assess the reliability of ultrasound in the assessment of humeral shaft fracture healing. The secondary aim was to estimate the accuracy of ultrasound assessment in predicting humeral shaft nonunion.

Twelve patients (mean age 54yrs [20–81], 58% [n=7/12] female) with a non-operatively managed humeral diaphyseal fracture were prospectively recruited and underwent ultrasound scanning at six and 12wks post-injury. Scans were reviewed by seven blinded observers to evaluate the presence of sonographic callus. Intra- and inter-observer reliability were determined using the weighted kappa and intraclass correlation coefficient (ICC). Accuracy of ultrasound assessment in nonunion prediction was estimated by comparing scans for patients that united (n=10/12) with those that developed a nonunion (n=2/12).

At both six and 12wks, sonographic callus was present in 11 patients (10 united, one developed a nonunion) and sonographic bridging callus (SBC) was present in seven patients (all united). Ultrasound assessment demonstrated substantial intra- (6wk kappa 0.75, 95% CI 0.47-1.03; 12wk kappa 0.75, 95% CI 0.46-1.04) and inter-observer reliability (6wk ICC 0.60, 95% CI 0.38-0.83; 12wk ICC 0.76, 95% CI 0.58-0.91). Absence of sonographic callus demonstrated a sensitivity of 50%, specificity 100%, positive predictive value (PPV) 100% and negative predictive value (NPV) 91% in nonunion prediction (accuracy 92%). Absence of SBC demonstrated a sensitivity of 100%, specificity 70%, PPV 40% and NPV 100% (accuracy 75%). Of three patients at risk of nonunion based on reduced radiographic callus formation (Radiographic Union Score for HUmeral fractures <8), one had SBC on 6wk ultrasound (and united) and the other two had non-bridging or absent sonographic callus (both developed a nonunion).

Ultrasound assessment of humeral shaft fracture healing was reliable and predictive of nonunion, and may be a useful tool in defining the risk of nonunion among patients with reduced radiographic callus formation.

The aims of this study in relation to distal radius fractures were to determine (1) the floor and ceiling effects for the QuickDASH and PRWE, (2) the floor and ceiling effects when defined to be within the minimal clinically important difference (MCID) of the minimal or maximal scores, (3) the degree to which patients with a floor or ceiling effect felt that their wrist was ‘normal’, and (4) patent factors associated with a floor or ceiling effect.

A retrospective cohort study of patients sustaining a distal radius fracture during a single year was undertaken. Outcome measures included the QuickDASH, PRWE, EQ-5D-3L and normal wrist score.

There were 526 patients with a mean age of 65yrs and 77% were female. Most patients were managed non-operatively (73%, n=385). The mean follow-up was 4.8yrs. A ceiling effect was observed for both the QuickDASH (22.3%) and PRWE (28.5%). When defined to be within the MCID of the best score, the effect increased to 62.8% for the QuickDASH and 60% for PRWE. Patients that achieved the best functional outcome according to the QuickDASH and PRWE felt their wrist was only 91% and 92% normal, respectively. Sex (p=0.000), age (p=0.000), dominant wrist injury (p=0.006 for QuickDASH and p=0.038 for PRWE), fracture type (p=0.015), and a better health-related quality of life (p=0.000) were independently associated with achieving a ceiling score.

The QuickDASH and PRWE demonstrated ceiling effects following a distal radius fracture. Patients achieving ceiling scores did not consider their wrist to be ‘normal’ for them.

This prospective randomised trial aimed to assess the superiority of internal fixation of well-reduced medial malleolar fractures (displacement □2mm) compared with non-fixation, following fibular stabilisation in patients undergoing surgical management of a closed unstable ankle fracture.

A total of 154 adult patients with a bi- or trimalleolar fracture were recruited from a single centre. Open injuries and vertically unstable medial malleolar fractures were excluded. Following fibular stabilisation, patients were randomised intra-operatively on a 1:1 basis to fixation or non-fixation after satisfactory fluoroscopic fracture reduction was confirmed. The primary outcome was the Olerud Molander Ankle Score (OMAS) at 12 months post-randomisation. Complications were documented over the follow-up period.

The baseline group demographics and injury characteristics were comparable. There were 144 patients reviewed at the primary outcome point (94%). The median OMAS was 80 (IQR, 60-90) in the fixation group vs. 72.5 (IQR, 55-90) in the non-fixation group (p=0.165). Complication rates were comparable, although significantly more patients (n=13, 20%) in the non-fixation group developed a radiographic non-union (p<0.001). The majority (n=8/13) were asymptomatic, with one patient requiring surgical reintervention. In the non-fixation group, a superior outcome was associated with an anatomical medial malleolar fracture reduction.

Internal fixation is not superior to non-fixation of well-reduced medial malleolar fractures when managing unstable ankle fractures. However, one in five patients following non-fixation developed a radiographic non-union and whilst the re-intervention rate to manage this was low, the longer-term consequences of this are unknown. The results of this trial may support selective non-fixation of anatomically reduced fractures.

Glenoid baseplate positioning for reverse total shoulder replacements (rTSR) is key for stability and longevity. 3D planning and image-derived instrumentation (IDI) are techniques for improving implant placement accuracy. This is a single-blinded randomised controlled trial comparing 3D planning with IDI jigs versus 3D planning with conventional instrumentation.

Eligible patients were enrolled and had 3D pre-operative planning. They were randomised to either IDI or conventional instrumentation; then underwent their rTSR. 6 weeks post operatively, a CT scan was performed and blinded assessors measured the accuracy of glenoid baseplate position relative to the pre-operative plan.

47 patients were included: 24 with IDI and 23 with conventional instrumentation. The IDI group were more likely to have a guidewire placement within 2mm of the preoperative plan in the superior/inferior plane when compared to the conventional group (p=0.01). The IDI group had a smaller degree of error when the native glenoid retroversion was >10° (p=0.047) when compared to the conventional group. All other parameters (inclination, anterior/posterior plane, glenoids with retroversion <10°) showed no significant difference between the two groups.

Both IDI and conventional methods for rTSA placement are very accurate. However, IDI is more accurate for complex glenoid morphology and placement in the superior-inferior plane. Clinically, these two parameters are important and may prevent long term complications of scapular notching or glenoid baseplate loosening.

Image-derived instrumentation (IDI) is significantly more accurate in glenoid component placement in the superior/inferior plane compared to conventional instrumentation when using 3D pre-operative planning. Additionally, in complex glenoid morphologies where the native retroversion is >10°, IDI has improved accuracy in glenoid placement compared to conventional instrumentation. IDI is an accurate method for glenoid guidewire and component placement in rTSA.

Anterior cruciate ligament (ACL) ruptures are debilitating injuries, often managed via ACL reconstruction (ACLR). Reduced range of motion (ROM), particularly loss of extension (LOE), is the most significant contributor to post-operative patient dissatisfaction. LOE may preclude return to sport, increase re-rupture rates and precipitate osteoarthritis.

Passive LOE rates following ACLR have been reported at 15%. However, LOE incidence during active tasks are poorly characterised. Our review sought to determine knee extension angles for active tasks following an ACL injury or ACLR. We hypothesised greater incidences of active LOE following ACL injury or ACLR, compared to uninjured contralateral limbs or controls.

We systematically searched MEDLINE, Embase, Cochrane Library, Scopus, SPORTDiscus, and relevant trials databases for English articles. Included were cohort, cross-sectional, case-controlled or randomised controlled trials analysing adults with ACL injury treated surgically or otherwise, with at least 12-weeks follow-up and reporting either active knee extension angle, active LOE angles or incidence of active knee LOE during functional tasks. The protocol was registered on PROSPERO (CRD42018092295). Subsequent meta-analysis was performed.

After screening, 71 eligible articles were included. Studies were heterogenous in design and quality. Included tasks were overground walking (n=44), running (n=3), hopping/jumping/cutting (n=11) single-leg landing (n=7), and stair climbing (n=6). LOE incidence varied depending on functional activities (33.95-92.74%). LOE incidence did not vary depending on ACL status (67.26% vs. 65.90% vs. 62.57% for ACL intact, ACLD and ACLR, respectively).

We observed no difference in active LOE incidence according to ACL status. Importantly, the observed incidence for active LOE was reliably higher than previously reported rates for passive measures.

Given the discrepancy between active and passive LOE incidence, clinicians may advisably prioritise active ROM during ACL rehabilitation.

Background

An improved understanding of intervertebral disc (IVD) structure and function is required for treatment development. Loading induces micro-fractures at the interface between the nucleus pulposus (NP) and the annulus fibrosus (AF), which is hypothesized to induce a cascade of cellular changes leading to degeneration. However, there is limited understanding of the structural relationship between the NP and AF at this interface and particularly response to load. Here, X-ray scattering is utilised to provide hierarchical morphometric information of collagen structure across the IVD, especially the interface region under load.

Aims

In total knee arthroplasty (TKA), blood loss continues internally after surgery is complete. Typically, the total loss over 48 postoperative hours can be around 1,300 ml, with most occurring within the first 24 hours. We hypothesize that the full potential of tranexamic acid (TXA) to decrease TKA blood loss has not yet been harnessed because it is rarely used beyond the intraoperative period, and is usually withheld from ‘high-risk’ patients with a history of thromboembolic, cardiovascular, or cerebrovascular disease, a patient group who would benefit greatly from a reduced blood loss.

The primary aim was to determine the rate of complications and re-intervention rate in a consecutive series of operatively managed distal radius fractures.

Data was retrospectively collected on 304 adult distal radius fractures treated at our institution in a year. Acute unstable displaced distal radius fractures surgically managed within 28 days of injury were included. Demographic and injury data, as well as details of complications and their subsequent management were recorded.

There were 304 fractures in 297 patients. The mean age was 57yrs and 74% were female. Most patients were managed with open reduction and internal fixation (ORIF) (n=278, 91%), with 6% (n=17) managed with manipulation and Kirschner wires and 3% (n=9) with bridging external fixation. Twenty-seven percent (n=81) encountered a post-operative complication. Complex regional pain syndrome was most common (5%, n=14), followed by loss of reduction (4%). Ten patients (3%) had a superficial wound infection managed with oral antibiotics. Deep infection occurred in one patient. Fourteen percent (n=42) required re-operation. The most common indication was removal of metalwork (n=27), followed by carpal tunnel decompression (n=4) and revision ORIF (n=4). Increasing age (p=0.02), male gender (p=0.02) and high energy mechanism of injury (p<0.001) were associated with developing a complication. High energy mechanism was the only factor associated with re-operation (p<0.001).

This study has documented the complication and re-intervention rates following distal radius fracture fixation. Given the increased risk of complications and the positive outcomes reported in the literature, non-operative management of displaced fractures should be considered in older patients.

Aims

A typical pattern of blood loss associated with total hip arthroplasty (THA) is 200 ml intraoperatively and 1.3 l in the first 48 postoperative hours. Tranexamic acid (TXA) is most commonly given as a single preoperative dose only and is often withheld from patients with a history of thromboembolic disease as they are perceived to be “high-risk” with respect to postoperative venous thromboembolism (VTE). The TRanexamic ACid for 24 hours trial (TRAC-24) aimed to identify if an additional 24-hour postoperative TXA regime could further reduce blood loss beyond a once-only dose at the time of surgery, without excluding these high-risk patients.

Aims

The primary aim of this study was to compare the hip-specific functional outcome of robotic assisted total hip arthroplasty (rTHA) with manual total hip arthroplasty (mTHA) in patients with osteoarthritis (OA). Secondary aims were to compare general health improvement, patient satisfaction, and radiological component position and restoration of leg length between rTHA and mTHA.

Fractures of the lateral clavicle with complete displacement have a high non-union rate and are associated with poor functional outcomes following non-operative treatment. Various operative techniques are available but preliminary studies of open reduction and tunnelled suspensory device (ORTSD) fixation report good early functional outcomes with a low rate of complications. This study assesses the functional outcomes in a large series of patients treated using ORTSD.

After surgical reconstruction in 67 patients, outcomes were assessed using the Disabilities of the Arm, Shoulder and Hand (DASH) questionnaire and Oxford score at six weeks, and three, six and twelve months post-operatively. 55 of 64 surviving patients were contacted at a mean of 69 (27–120) months to complete DASH and Oxford scores, evaluate overall satisfaction, and document any complications.

At one year post-operatively, the mean Oxford score was 46.4 and mean DASH score was 2.4 points (59/67 patients assessed). At a mean of 69 months after surgery, the mean Oxford score was 46.5 and mean DASH score was 2.2 (55 surviving and contactable patients). There were no significant differences between the one-year functional scores and those at the latest follow-up. Two patients developed symptomatic non-union requiring re-operation, and two developed an asymptomatic fibrous union not requiring surgery. The five-year survival when considering only obligate revision for implant-related complications was 97.0%.

ORTSD fixation for isolated displaced lateral-end clavicle fractures in medically-fit patients is associated with good functional outcomes, and a low rate of medium-term complications. Routine removal of the implant was not necessary.

Aims

The primary aim of the study was to compare the knee-specific functional outcome of robotic unicompartmental knee arthroplasty (rUKA) with manual total knee arthroplasty (mTKA) for the management of isolated medial compartment osteoarthritis. Secondary aims were to compare length of hospital stay, general health improvement, and satisfaction between rUKA and mTKA.

Introduction

Opioid abuse is a national epidemic. Traditional pain management after total knee arthroplasty (TKA) relied heavily on opioids. The evidence that in-hospital multimodal pain management (MMPM) is more effective than opioid-only analgesia is overwhelming. There has been little focus on post-discharge pain management. The purpose of this study was to determine whether MMPM after TKA could reduce opioid consumption in the 30-day period after hospital discharge.

Aims

Accurate placement of the acetabular component is essential in total hip arthroplasty (THA). The purpose of this study was to determine if the ability to achieve inclination of the acetabular component within the ‘safe-zone’ of 30° to 50° could be improved with the use of an inclinometer.

Accurate placement of the acetabular component is essential in Total Hip Arthroplasty (THA). The purpose of this study is to determine if an analog spirit level can improve the surgeon's ability to achieve acetabular inclination within the “safe-zone” of 30 to 50 degrees.

We reviewed 167 primary THAs performed by a single surgeon over 14 months. Procedures were performed at two facilities, an inpatient hospital where a spirit level was utilized and an ambulatory facility where it was not. We excluded 47 patients with a BMI>40, age>68 or a surgical indication other than osteoarthritis who were not candidates for the ambulatory center. Cup inclination angles were measured from de-identified plain radiographs by two blinded investigators not involved in the index procedures. The effect of level usage on inclination angle was determined using multivariate regression analysis.

The mean inclination angle for the 68 hips performed with the level was 42.9 degrees (95% CI: 41.7–44.0) compared to 46.5 degrees (95% CI: 45.2–47.7) for the 52 hips without it (p<.001). Regression analysis demonstrated a 9.1% difference in cup inclination due to the level (p<.001), and THAs performed without the level were 3 times more likely to result in inclinations > 50 degrees (OR 2.8, p=.036). The two investigators' measurements demonstrated a correlation of 0.95 (95% CI: 0.93–0.97).

Use of a simple spirit level resulted in a significant reduction in the number of outliers compared to the freehand technique. The spirit level may be a simple and inexpensive tool to improve acetabular component abduction angles.

Background

Intraoperative blood loss is a known potential complication of total knee arthroplasty (TKA). Tranexamic acid (TXA) has been shown to reduce intraoperative blood loss and postoperative transfusion in patients undergoing TKA. While there are numerous studies demonstrating the efficacy of intravenous and topical TXA in patients undergoing TKA, there are comparatively few demonstrating the effectiveness and appropriate dosing recommendations of oral formulations.

Introduction

A common phenomenon occurring as a result of reverse total shoulder arthroplasties (RSA) is scapular notching. While bone loss of the scapula may be quantified using radiographic techniques,[1] the material loss on the humeral bearing has not been quantified. Depending on their functional biological activity, a high volume of polyethylene wear particles has been shown to be related to osteolysis, bone loss and ultimately, loosening of implants in other joints.[2] In order to understand the threshold for osteolysis in the shoulder, it is important to have a method that can accurately quantify the amount of material loss. The aim of this research was to (I) create and validate a method for quantifying material loss from a single humeral implant design which can then (II) be used to measure retrieved devices.

Introduction

The major function of the medial meniscus has been shown to be distribution of the load with reduction of cartilage stresses, while its role in AP stability has been found to be secondary. However several recent studies have shown that cartilage loss in OA occurs in the central region of the tibia while the meniscus is displaced medially. In a lab study (Arno, Hadley 2013) it was confirmed that the AP laxity was greatly reduced with a compressive force across the knee, while the femur shifted posteriorly and the AP laxity was increased after a partial meniscetomy of the posterior horn. It is therefore possible that under load, the compression of the meniscus and the cartilage, 2–3mm in total, allows load transmission on the central tibial plateau, and causes radial expansion and tension of the meniscus providing restraint to femoral displacements. This leads to our hypotheses that the highest loading on the medial meniscus would be at the extremes of motion, rather than in the mid-range, and that the meniscus would provide the majority of the restraint to anterior-posterior femoral displacements throughout flexion when compressive loads were acting.

PURPOSE

Soft tissue balancing can be achieved by using spacer blocks, by distractors which measure tensile forces, or by instrumented devices which measure the forces on the lateral and medial condyles. However there is no quantitative method for assessment of balancing at clinical follow-up; to address this, we developed a Smart Knee Fixture (SKF) which measured the varus and valgus angles for a moment of 10 Nm. Our purpose was to determine if varus and valgus angles measured at clinical follow-up, was equivalent to the balancing parameters of distraction forces or contact forces measured at surgery.

PURPOSE

Soft tissue balancing can be achieved by using spacer blocks, by distractors which measure tensile forces, or by instrumented devices which measure the forces on the lateral and medial condyles. However there is no quantitative method for assessment of balancing at clinical follow-up; to address this, we developed a Smart Knee Fixture (SKF) which measured the varus and valgus angles for a moment of 10 Nm. Our purpose was to determine if varus and valgus angles measured at clinical follow-up, was equivalent to the balancing parameters of distraction forces or contact forces measured at surgery. METHODS: The SKF, which measured VV angles using stretch sensors on each side of the knee, was validated by cadaver studies, fluoroscopy, and emg. The balancing parameters were:

A force analysis, and measurements on 101 surgical cases & clinical follow-up in an IRB study, were carried out to determine the relationship between these parameters.

Introduction

Evaluation of post-operative soft tissue balancing outcomes after Total Knee Arthroplasty (TKA) and other procedures can be measured by stability tests, with Anterior-Posterior (AP) drawer tests and Varus-Valgus (VV) ligamentous laxity tests being particularly important. AP stability can be quantified using a KT1000 device; however there is no standard way of measuring VV stability. The VV test relies on subjective force application and perception of laxity. Therefore we sought to develop and validate a device and method for quantifying knee balancing by analyzing VV stability.

The use of smart trial components is now allowing a better assessment of soft tissue balancing at the time of total knee replacement surgery. A balanced knee can be defined as one that possesses symmetry, ie. equal and centered lateral and medial forces through the full range of flexion. There is still a need for a standard reproducible surgical test to quickly confirm optimized balancing at surgery with such devices. The Heel Push test is the established standard, by pushing the foot in a cephalad direction while supporting the thigh and keeping the leg stable in the vertical plane. A common variation of this test is the Thigh Pull test where the foot is actively assisted during the cephalad pull of the thigh through deep flexion. The test is an open chain test. The Thigh Pull test may be an improvement since the weight of the leg is alleviated and no supplemental compressive forces are introduced. The directional changes of the lower extremity are thus a result of ligamentous tension and balances. The purpose of this study is to compare the two tests using a standard testing methodology and observe the variation in kinetic parameters in a controlled biomechanical setting.

A custom l rig was developed, which independently controls all six degrees of freedom about the knee joint. In addition a commercial navigation system was used to derive instantaneous alignment values and flexion angles between the tibia and femur. The pelvis was fixed to the table and the foot was fitted onto a low friction carriage along a slide rail. The knee design used was cruciate retaining. The pressure mapping system was a wireless tibial trial that provided magnitude of load per compartment.

The study is a preliminary cadaveric study reporting the data from two. In this experiment the leg was then tested with the Heel Push and Thigh Pull tests after obtaining optimum soft tissue balance of the cadaveric specimen. From this standard neutral state a series of single surgical variables were introduced to mimic common intra-operative surgical corrections. This was achieved through custom tibial liner and angle shims.

The results defied theoretical anticipation. Though the total contact forces with heel push were generally higher than with thigh pull, the relative load distribution between compartments did not follow a trend (see Figure 1). Furthermore in deeper flexion the persistence of relatively high contact pressures would suggest that ligaments still generate intra-articular forces despite the much weaker gravitational effect. The clinical relevance lies in the asymmetry of the load distribution between medial and lateral compartment for the two methods tested. The load asymmetry as tested by the Thigh Pull test may correspond to an open chain in swing phase. This asymmetry would force some axial rotation and tibial femoral alignment deviation that can significantly affect the forces at the time of heel strike. The Heel Push test would be more representative of the compressive forces in a closed chain mode as seen during the stance phase of gait.

There are many different approaches to achieving balancing in total knee surgery. The most frequently used method is to obtain correctly aligned bone cuts, and then carry out necessary soft tissue releases to achieve equal flexion and extension gaps. In some techniques, the bone cuts themselves are determined by the prevailing soft tissue status or the kinematics during flexion-extension. Navigation can provide quantitative data during these processes but so far, navigation is used in only in a minority of cases. However in recent years, new technologies have been introduced with lower cost and implementation time, allowing for more widespread use. Early studies have indicated that more reproducible balancing can be obtained, and that balancing has a positive effect on clinical outcomes. However the ability to measure balancing quantitatively during surgery, has raised the questions of the most systematic method for implementation during surgery, and the relative influence of various correcting factors. Further, the ideal balancing parameters with respect to varus-valgus ratios and the magnitudes during a full flexion range, have yet to be defined. Even if normative data is the target, there is scant data on this topic.

In our own laboratory, we carried out experiments on knee specimens where the various surgical variables were systematically investigated for their effect on varus-valgus balancing. Different tests were developed including the ‘Heel Push Test’ where lateral and medial contact forces were plotted as a function of flexion. Imbalances were achieved with either bone cut adjustments or soft tissue releases. The major finding was that adjustments of only 2 mms or 2 degrees could correct most imbalances. This was considered to be due to two effects; the pretension in the ligaments bringing the structure to the stiff part of the load-elongation curve, and the high values of the stiffness itself. Medial-lateral equality was the goal in this work, but recognizing that this may not be the situation in the normal knee. To answer this question, we developed a method for measuring the varus-valgus balancing in normal subjects, using a ‘Smart Knee Fixture’ with embedded stretch sensors. We validated this device using cadaveric specimens, and normal volunteers using fluoroscopy and electromyography. We are now applying the method in an IRB study to both normals and post-operative knee replacement cases. For the latter, the relation between operative data, and post-operative balancing will be studied, as well as the relation of balancing to functional outcomes.

This overall subject of balancing at surgery, and the post-operative effects, is open to extensive experimental research, and is predicted to result in improved outcomes.

Soft tissue balancing in total knee replacement may well be the determining factor in raising the fair patient satisfaction. The development of intelligent implants allows quantification of reactive loads to applied pressures. This can be tested in dynamic mode such as heel push test at surgery, or in static mode such as when testing for varus/valgus (VV) laxity of the collateral ligaments of the knee. We postulate that a well-balanced knee will have comparable if not equal load distribution across compartments in dynamic loading. When tested for laxity, we anticipate an equal or comparable response to VV applied loads under physiologic load range of 10–50N. This study sought to analyze the relationship between the kinematic (joint motion) and kinetic (force) effects to VV testing in the 0–15 degrees range of flexion. One goal was to demonstrate that testing the knee in locked extension (Screw Home effect) is unreliable and should be abandoned in favor of the more reliable VV testing at 10–15 degrees of flexion.

This is a preliminary cadaveric study utilizing data from two hemibodies. The pelvis was fixed in a custom test rig with open or closed chain lower leg testing capability along a sliding rail with foot VV translational. Forces were applied at the malleoli with a wireless hand held dynamometer. Kinematic analysis of the hip-knee-ankle (HKA) tibiofemoral angle was derived from a commercial navigation system with mounted infrared trackers. Kinetic analysis was derived from a commercially available sensor imbedded in a tibial trial liner. Balance was optimized by conventional methods with the use of the sensor feedback until loads were roughly symmetrical and VV testing yielded symmetrical rise in opposite compartments. The VV testing was then performed with the knees locked at the femoral side in axial rotation and translational motion in any plane. Sagittal flexion was pre-set at 0, 10, and 15 degrees and progressive load was applied.

Total Knee Arthroplasty (TKA), has now become a reliable, successful, and widely used treatment for osteoarthritis. Numerous reports indicate that for the majority of patients, the TKA lasts a lifetime with pain relief and the ability to perform most everyday activities. However there are a number of ways in which the procedure can be further improved, the focus here being on function. One of the problems in evaluating function is that it depends upon the inherent ability, motivation, and expectation of the patients. There are several well-used questionnaire systems which capture functional ability objectively. In the effort to simplify evaluation, a ‘forgotten knee’ evaluation has been introduced, the concept being that ‘the ideal TKA design’ would feel and function like a normal knee. Such a measure would include factors such as surgical technique, alignment, and rehabilitation, as well as the TKA design itself. Another approach to evaluation is to measure biomechanical parameters, such as in gait analysis and fluoroscopy, which evaluate kinematic or kinematic parameters, using normal controls for comparison. Nevertheless, such evaluations still include factors other than the TKA design itself, and do not apply to new designs.

The approach taken here for the evaluation of a new TKA design independent of other factors, is to measure the neutral path of motion and the laxity boundaries of the loaded knee on the application of shear and torque over a full range of flexion. The benchmark is the same kinematic data from the normal intact knee. The rationale has some analogy to the ‘forgotten knee’ in that if the laxity response of a design of TKA is the same as that of the anatomic knee itself, the behavior of that implanted knee in any functional condition will be indistinguishable from that of the anatomic knee itself. Such a testing concept has some similarities to the constraint test described in the ASTM standard. In this paper, a novel design algorithm is proposed for creating different design concepts. First, a general morphological form is formulated for each design concept, a Cam-Post PS, a Saddle-Ramp, and a Converging Condyle, all with overall anatomic-like surfaces. Each femoral component is then designed, which is then moved through the normal neutral path and laxity paths, which creates the tibial surface. The concepts are evaluated using a Desktop Knee Machine configured to move the knee dynamically through full flexion while applying combinations of compression, shear and torque; kinematic data being captured optically and plotted using custom software. The normal benchmark was obtained from 10 normal knee specimens, which showed the restraint of the medial femoral condyle to anterior displacement and the overall rollback and laxity laterally. Compared with standard CR and PS designs, the Guided Motion designs were seen to more closely resemble normal. It is proposed that this approach can result in designs which will more likely reproduce a ‘forgotten knee’ and achieve the optimal function for a given patient.

Aim

This study aims to elucidate the effects of radiofrequency chondroplasty (RFC), a surgical technique for the treatment of damaged articular cartilage, at a microscopic scale. Here we report about two aspects of the study – a morphological analysis of the treated surface using nonlinear microscopy and Raman spectroscopy, and an investigation into changes in permeability to large and small molecules. Cartilage samples were obtained from

We report our experience of using a computer navigation system to aid resection of malignant musculoskeletal tumours of the pelvis and limbs and, where appropriate, their subsequent reconstruction. We also highlight circumstances in which navigation should be used with caution.

We resected a musculoskeletal tumour from 18 patients (15 male, three female, mean age of 30 years (13 to 75) using commercially available computer navigation software (Orthomap 3D) and assessed its impact on the accuracy of our surgery. Of nine pelvic tumours, three had a biological reconstruction with extracorporeal irradiation, four underwent endoprosthetic replacement (EPR) and two required no bony reconstruction. There were eight tumours of the bones of the limbs. Four diaphyseal tumours underwent biological reconstruction. Two patients with a sarcoma of the proximal femur and two with a sarcoma of the proximal humerus underwent extra-articular resection and, where appropriate, EPR. One soft-tissue sarcoma of the adductor compartment which involved the femur was resected and reconstructed using an EPR. Computer navigation was used to aid reconstruction in eight patients.

Histological examination of the resected specimens revealed tumour-free margins in all patients. Post-operative radiographs and CT showed that the resection and reconstruction had been carried out as planned in all patients where navigation was used. In two patients, computer navigation had to be abandoned and the operation was completed under CT and radiological control.

The use of computer navigation in musculoskeletal oncology allows accurate identification of the local anatomy and can define the extent of the tumour and proposed resection margins. Furthermore, it helps in reconstruction of limb length, rotation and overall alignment after resection of an appendicular tumour.

Cite this article: Bone Joint J 2015;97-B:258–64.

The number of primary Total Knee Arthroplasty (TKA) and primary Total Hip Arthroplasty (THA) procedures carried out in England and Wales is increasing annually. The British Orthopaedic Association guidelines for follow up currently differ for patients with TKA and THA. In THA the BOA recommends that Orthopaedic Data Evaluation Panel (ODEP) 10A rated implants should be followed up in the first year, once at seven years and three yearly thereafter. The BOA guidelines for TKA minimum requirement is radiographs at 5 years and each five years thereafter. Few studies have investigated if early follow up affects patient management following total hip and knee arthroplasty

We carried out a retrospective review of all revision procedures carried out in our institution between April 2010 to April 2013. The medical notes and radiographs for each patient were examined to determine the operative indications and patients symptoms. 92 knee revisions and 143 hip revisions were identified. Additionally we retrospectively reviewed the outcome of 300 one year routine arthroplasty follow up appointments.

The mean time of hip revision was 8.5years (range 0 to 27years) and 5.6years (range 0 to 20years) for knee revisions. The commonest cause for revision was aseptic loosening associated with pain in 49 (53%) of knee revision patients and 89 (63%) of hip revisions. Infection accounted for 26 (28%) knee revisions and 16 (12%) hip revisions. Only 1% of hip and knee revisions was carried out in asymptomatic patients with aseptic loosening.

We did not identify any cases were a patients management was altered at the routine arthroplasty review clinic and none were referred on for further surgical treatment. The findings of our study suggest there is no evidence for a routine one year arthroplasty review and revisions were carried out in asymptomatic patients in 1% of patients.

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.

Myotome values for the upper limb appear to have been established in the early twentieth century based on historical work. Supraclavicular brachial plexus injuries present with a pattern of neurological loss consistent to the nerve roots affected. Recent advances in radiological imaging and intraoperative nerve stimulation have allowed confirmation of the affected nerve roots.

The records of 43 patients with partial injuries to the supraclavicular brachial plexus were reviewed. The injuries covered the full range of injury patterns including those affecting C5, C5-6, C5-7, C5-8, C7-T1 and C8-T1 roots. All cases with upper plexus injuries had surgical exploration of the brachial plexus with the injury pattern being classified on the basis of whether the roots were in continuity, ruptured, or avulsed, and, if seen in continuity, the presence or absence of a response to stimulation. For lower plexus injuries the classification relied on identification of avulsed roots on Magnetic Resonance Imaging. Muscle powers recorded on clinical examination using the MRC grading system.

In upper plexus injuries paralysis of flexor carpi radialis indicated involvement of C7 in addition to C5-6, and paralysis of triceps and pectoralis major suggested loss of C8 function. A major input from T1 was confirmed for flexor digitorum superficialis, flexor digitorum profundus (FDP) to the radial digits, and extensor pollicis longus. C8 was the predominant innervation to the ulnar side of FDP and intrinsic muscles innervated by the ulnar nerve with some contribution from C7.

A revised myotome chart for the upper limb is proposed.

Balancing in total knee replacement is generally carried out using the feel and experience of the surgeon, using spacer blocks or distractors. However, such a method is not generally applicable to all surgeons and nor does it provide quantitative data of the balancing itself. One approach is the use of instrumented distractors, which have been used to monitor soft tissue releases or indicate a flexion cut for equal lateral and medial forces. More recently an instrumented tibial trial has been introduced which measures and displays the magnitude and location of the loads on the lateral and medial plateaus, during various manoeuvres carried out at surgery. The data set is then used by the surgeon to determine options, whether soft tissue releases or bone cut adjustments, to achieve lateral-medial equality.

The testing method consisted of mounting the femoral component rigidly in a fixture on the vertical arm of an MTS machine. The tibial component was fixed on to a platform which allowed varus-valgus correction, and where the component could be displaced or rotated in a horizontal plane. Two of each size times 4 sizes of production components were tested. Compressive forces from 0–400N in steps of 50N were applied and the readings taken. There were strong correlations between applied and measured forces with mean Pearson's Correlation Coefficient of 0.958.

The special tests under different conditions did not have any effect on the output values. The output data proved to be repeatable under Central Loading with a maximum standard deviation of ± 15.36N at the highest applied force of 400N. “Low battery” did not adversely affect the data. Applying the load steadily to maximum versus load-unload-zero tests produced similar results. Lubrication versus no lubrication tests produced no changes to the results. There was no cross talk of the electronics within the device when loaded on one condyle. For both central and anterior-posterior loading, the contact points were centered medial-lateral on the GUI display, and tracked contact point translation appropriately.

Anterior-posterior loading did create output load variance at the extremes. However, it enabled the validation of the relationship of the femur on the trial surface. In addition, malrotation would be indicated by the femur riding up on the anterior or posterior tibial edges, important for soft tissue tension in all flexion angles.

In conclusion, the sensors provided data which was accurate to well within a practical range for surgical conditions. In our separate experiments on 10 cadaveric leg specimens, even the same test under controlled conditions could produce variations of up to ± 30N. Hence the sensor outputs indicated whether or not the knee was balanced to that level of tolerance, while the contact point data would indicate contacts too close to the anterior or posterior of the tibial surface.

The purpose of balancing in total knee surgery is to achieve smooth tracking of the knee over a full range of flexion without excessive looseness or tightness on either the lateral or medial sides. Balancing is controlled by the alignment of the bone cuts, the soft tissue envelope, and the constraint of the total knee. Recently, Instrumented Tibial Trials (OrthoSensor) which measure and display the location and magnitude of the forces on the lateral and medial condyles, have been introduced, offering the possibly of predictive and quantitative balancing. This paper presents the results of experiments on 10 lower limb specimens, where the effects of altering the bone cuts or the femoral component size were measured.

A special leg mounting rig was fixed to a standard operating table. A boot was strapped to the foot, and the boot tracked along a horizontal rail to allow flexion-extension. The initial bone cuts were carried out by measured resection using a navigation system. The trial femoral component and the instrumented tibial trial were inserted, and the following tests carried out:

Sag Test; foot lifted up, the trial thickness chosen to produce zero flexion.

Heel Push Test; heel moved towards body to maximum flexion.

Varus-Valgus Test, AP and IXR Tests were also carried out, but not discussed here.

For an initial state of the knee, close to balanced, the lateral and medial contact forces were recorded for the full flexion range. The mean value of the contact forces per condyle was 77.4N, the mean in early flexion (0–60 deg) was 94.2N, and the mean in late flexion (60–120 deg) was 55.7N. The difference was due to the effect of the weight of the leg. One of the following Surgical Variables was then implemented, and the contact forces again recorded. 1.

Distal femoral cut; 2 mm resection (2 mm increase in insert thickness to preserve extension)

The differences between the condyle force readings before and after the Surgical Variable were calculated for low and high angular ranges. The mean values for the 10 knees of the differences of the above Surgical Variables from the initial balanced state are shown in the chart.

From literature data, the mean tension increase in one collateral ligament is close to 25N/mm up to the toe of the load-elongation graph, and 50N/mm after the toe. Hence in the initial balanced state, the collateral ligaments were elongated by 2–4 mm producing pretension. From the Surgical Variables data, up to 2 mm/2 deg change in bone cuts (or 3 mm femcom change), and collateral ligament releases up to 2 mm, would correct from any unbalanced state to a balanced state.

This data provides useful guidelines for the use of the Instrumented Tibial Trials at surgery, in terms of bone cut adjustments and ligament releases.

Obtaining accurate bone cuts based on mechanical axes and ligament balancing, are necessary for a successful total knee procedure. The OrthoSensor Tibial Trial displays on a GUI the magnitude and location of the lateral and medial contact forces at surgery. The goal of this study was to develop algorithms to inform the surgeon which bone cuts or soft tissue releases were necessary to achieve balancing, from an initial unbalanced state.

A rig was designed for lower body specimens mounted on a standard operating table. SURGICAL TESTS were then defined: Sag Test, leg supported at the foot; Dynamic Heel Push test, flexing to 120 degrees with the foot sliding along a rail; Varus-Valgus test; AP Drawer test; Internal-External Rotation test. The bone cuts were made using a Navigation system, matching the Triathlon PCL retaining knee. To determine the initial thickness of the tibial trial, the Sag Test was performed to reach 0 deg flexion. The Heel Push Test was then performed to check the AP position of the lateral and medial contacts, from which the rotational position of the tibial tray was determined. Pins were used to reproduce this position during the experiments.

SURGICAL VARIABLES were then defined, which would influence the balancing: LCL Stiffness, MCL Stiffness, Distal Femoral Cut Level, Tibial Sagittal Slope, Tibial Varus or Valgus, and AP Femoral Component Length. Balancing was defined as equal lateral and medial forces due to soft tissue tensions throughout the flexion range, equal varus and valgus stiffnesses, and no contacts closer than 10 mm to component edges. All of the above tests were then performed sequentially, and the changes in the contact force readings were considered as a signature of that Surgical Variable.

Testing was carried out on 10 full leg specimens. The Sag Test was the basic test for determining the thickness of the tibial insert. The Heel Push Test was then implemented from which force data throughout flexion was determined; followed by the Varus-Valgus Test. In a surgical case, this data will be used in a decision tree to identify which Surgical Variable required correction. In the experiments, by obtaining the above data for each SURGICAL VARIABLE in turn, we were able to determine a SIGNATURE for each SURGICAL VARIABLE. It was found that there was considerable variation in the force magnitudes between knees. However the SIGNATURES were sufficient to point to the specific SURGICAL VARIABLE requiring correction. In some knees, although there was a dominant SURGICAL VARIABLE, even after correcting for that, there was still an imbalanced state, requiring a second correction.

This research provided the fundamental principles and data for: 1.

Defining tests to be carried out at surgery, to obtain force data to determine the SURGICAL VARIABLE to correct.

INTRODUCTION:

The purpose of this study was to determine if a short femoral stem (Lima Corporate, Udine, Italy) would result in a strain distribution which mimicked the intact bone better than a traditional length stem, thereby eliminating the potential for stress-shielding.

Introduction

Two randomised trials concluded cast type (above or below elbow) makes no significant difference in the re-displacement rate of paediatric forearm fractures involving the distal third of the radius. This has not, however, led to the universal use of below elbow casts. In particular we noted one trial reported significant re-displacement in 40% or more of cases, which was much higher than we would expect.

To review the radiological outcomes and need for re-manipulation of paediatric distal forearm fractures treated with closed manipulation under anaesthesia in our institution, in part for subsequent comparison with published results.

All forearm fractures treated at a specialist children's hospital in one year were reviewed retrospectively. Based on the methodology of one trial, we included all fractures involving the distal third of the radius, with or without an ulna fracture, which underwent closed manipulation. Outcomes were radiological alignment using existing radiographs and need for re-manipulation. Cast type was at the discretion of the treating surgeon. The radiological criteria for re-displacement were based on published methodology.

79 children underwent manipulation, 71 receiving above elbow casts and 8 below elbow casts. Radiologically 21% of injuries treated in an above elbow cast re-displaced (15/71) compared to 38% of those in below elbow plasters (3/8). In 2 cases the re-displacement was treated with re-manipulation.

The preference in our institution was clearly for above elbow casts in this injury pattern. The small number of below elbow casts in our series limits any comparisons. Our rate of re-displacement using above elbow casts was half that of one of the published studies, so the existing literature is not consistent with our experience.

The surgical management of musculoskeletal tumours is a challenging problem, particularly in pelvic and diaphyseal tumour resection where accurate determination of bony transection points is extremely important to optimise oncologic, functional and reconstructive options. The use of computer assisted navigation in these cases could improve surgical precision and achieve pre-planned oncological margins with improved accuracy.

We resected musculoskeletal tumours in ten patients using commercially available computer navigation software (Orthomap 3D, Stryker UK Ltd). Of the five pelvic tumours, two underwent biological reconstruction with extra corporeal irradiation, two endoprosthetic replacement (EPR) and one did not require bony reconstruction. Three tibial diaphyseal tumours had biological reconstruction. One patient with proximal femoral sarcoma underwent extra-articular resection and EPR. One soft tissue sarcoma of the adductor compartment involving the femur was resected with EPR.

Histological examination of the resected specimens revealed tumour free margins in all cases. Post-operative radiographs and CT show resection and reconstruction as planned in all cases. Several learning points were identified related to juvenile bony anatomy and intra-operative registration.

The use of computer navigation in musculoskeletal oncology allows integration of local anatomy and tumour extent to identify resection margins accurately. Furthermore, it can aid in reconstruction following tumour resection. Our experience thus far has been encouraging. Further clinical trials are required to evaluate its long-term impact on functional & oncological outcomes.

Primary bone tumours of the clavicle are rare. Currently the existing literature is limited to a single case series and case reports or cases. Information regarding the patient's demographics and tumour types is therefore limited.

The aim of this study was to investigate the and also suggest a management protocol for suspected primary bone tumours of the clavicle. We retrospectively reviewed the Scottish Bone Tumour Register from January 1971 to January 2012 and included all primary bone tumours of the clavicle.

We identified only sixteen primary bone tumours over forty one year's highlighting the rarity of these tumours. There were ten benign and six malignant tumours with a mean age of 32 years (Range 4 to 66). The average presentation to orthopaedics after onset of symptoms was two months with five patients presenting following a pathological fracture. Malignant tumour types identified were consistent with previous literature with two cases of Ewing's sarcoma and osteosarcoma and a single case of osteosarcoma post radiotherapy and a single case of chondrosarcoma. Benign tumours were treated effectively with intralesional procedures. Malignant tumours were treated with wide local excision and subtotal or total clavicle excision.

We suggest an investigatory and treatment protocol for patients with a suspected primary bone tumour of the clavicle. This is the largest series of primary bone tumours of the clavicle in the literature.

Metal artefact reduction (MAR) MRI is now widely considered to be the standard for imaging metal-on-metal (MoM) hip implants. The Medicines and Healthcare Products Regulatory Agency (MHRA) has recommended cross-sectional imaging for all patients with symptomatic MoM bearings. This paper describes the natural history of MoM disease in a 28 mm MoM total hip replacement (THR) using MAR MRI. Inclusion criteria were patients with MoM THRs who had not been revised and had at least two serial MAR MRI scans. All examinations were reported by an experienced observer and classified as A (normal), B (infection) or C1–C3 (mild, moderate, severe MoM-related abnormalities). Between 2002 and 2011 a total of 239 MRIs were performed on 80 patients (two to four scans per THR); 63 initial MRIs (61%) were normal. On subsequent MRIs, six initially normal scans (9.5%) showed progression to a disease state; 15 (15%) of 103 THRs with sequential scans demonstrated worsening disease on subsequent imaging.

Most patients with a MoM THR who do not undergo early revision have normal MRI scans. Late progression (from normal to abnormal, or from mild to more severe MoM disease) is not common and takes place over several years.

Cite this article: Bone Joint J 2013;95-B:1035–9.

The surgical management of musculoskeletal tumours is a challenging problem, particularly in pelvic and diaphyseal tumour resection where accurate determination of bony transection points is extremely important to optimise oncologic, functional and reconstructive options. The use of computer assisted navigation in these cases could improve surgical precision.

We resected musculoskeletal tumours in fifteen patients using commercially available computer navigation software (Orthomap 3D). Of the eight pelvic tumours, three underwent biological reconstruction with extra corporeal irradiation; three endoprosthetic replacement (EPR) and two required no bony reconstruction. Four diaphyseal tumours had biological reconstruction. Two patients with proximal femoral sarcoma underwent extra-articular resection and EPR. One soft tissue sarcoma of the adductor compartment involving the femur was resected with EPR.

Histological examination of the resected specimens revealed tumour free margins in all cases. Post-operative radiographs and CT show resection and reconstruction as planned in all cases. Several learning points were identified related to juvenile bony anatomy and intra-operative registration.

The use of computer navigation in musculoskeletal oncology allows integration of local anatomy and tumour extent to identify resection margins accurately. Furthermore, it can aid in reconstruction following tumour resection. Our experience thus far has been encouraging.

We report the short term follow up of nineteen consecutive PFC sigma unicompartmental knee replacements carried out in our institution with minimum one year follow up. The PFC Sigma medial unicompartmental knee replacement is a fixed bearing, cemented unicompartmenal knee replacement. There are currently no published reports of follow up for the PFC Sigma medial unicompartmental knee replacement.

Nineteen patients (nineteen knees) underwent PFC sigma medial unicompartmental knee arthroplasty. The pre-operative diagnosis was osteoarthritis in eighteen patients and osteonecrosis in one patient. There were ten males and nine females with a mean age of sixty four years. All patients had clinical and radiological review at one year. All operations were carried out by the two senior authors (BPR and BL).

The mean length of admission was 2.7 days (Range 2–5). There have been no infective or thromboembolic complications to date. The mean oxford scores improved from 41 (Range 26–52) pre-operatively to 18 (15–27) at one year follow-up. The mean range of motion improved from 115 degrees of flexion preoperatively to 125 degrees. All radiographs were satisfactory at one year follow up with no evidence of loosening.

We report the promising early results of a new medial unicompartmental knee replacement with at least one year follow up. No early complications or infections were identified in our cohort of patients.

Current knowledge regarding upper limb myotomes is based on historic papers. Recent advances in magnetic resonance imaging (MRI) and surgical exploration with intraoperative nerve stimulation now allow accurate identification of nerve root injuries in the brachial plexus. The aim of this study is to identify the myotome values of the upper limb associated with defined supraclvicular brachial plexus injuries.

57 patients with partial supraclavicular brachial plexus injuries were identified from the Scottish brachial plexus database. The average age was 28 years and most injuries secondary to motor cycle accidents or stabbings. The operative and MRI findings for each patient were checked to establish the root injuries and the muscle powers of the upper limb documented.

The main patterns of injuries identified involved (C5,6), (C5,6,7), (C5,6,7,8) and (C8, T1). C5, 6 injuries were associated with loss of shoulder abduction, external rotation and elbow flexion. In 30% of the 16 cases showed some biceps action from the C7 root. C5,6,7 injuries showed a similar pattern of weakness with the additional loss of flexor carpi radialis and weakness but not total paralysis of triceps in 85% of cases. C5,6,7,8 injuries were characterised by loss of pectoralis major, lattisimus dorsi, triceps, wrist extension, finger extension and as well as weakness of the ulnar intrinsic muscles. We identified weakness of the flexor digitorum profundus to the ulnar sided digits in 83% of cases. T1 has a major input to innervation of flexors of the radial digits and thumb, as well as intrinsics.

This is the largest study of myotome values in patients with surgically or radiologically confirmed injuries in the literature and presents information for general orthopaedic surgeons dealing with trauma patients for the differentiation of different patterns of brachial plexus injuries. In addition we have identified new anatomical relationships not previously described in upper limb myotomes.

Obtaining accurate bone cuts based on mechanical axes and ligament balancing, are necessary for a successful total knee procedure. The Orthosensor Tibial Trial displays on a GUI the magnitude and location of the lateral and medial contact forces at surgery. The goal of this study was to develop the algorithms to inform the surgeon which bone cuts or soft tissue releases were necessary to achieve balancing, from an initial unbalanced state.

A rig was designed for lower body specimens mounted on a standard operating table. Surgical Tests were then defined: Sag Test, leg supported at the foot; Dynamic Heel Push test, flexing to 120 degrees with the foot sliding along a rail; Varus-Valgus test; AP Drawer test; Internal-External Rotation test. The bone cuts were made using a Navigation system, to match the Triathlon PCL retaining knee. To determine the initial thickness of the tibial trial, the Sag Test was performed to reach 0 deg flexion. The Heel Push Test was then performed to check the AP position of the lateral and medial contacts, from which the rotational position of the tibial tray was determined. Pins were used to reproduce this position during the experiments.

Surgical Variables were then defined, which would influence the balancing: LCL Stiffness, MCL Stiffness, Distal Femoral Cut Level, Tibial Sagittal Slope, Tibial Varus or Valgus, and AP Femoral Component Length. Balancing was defined as equal lateral and medial forces due to soft tissue tensions throughout the flexion range, equal varus and valgus stiffnesses, and no contacts closer than 10mm to component edges. All of the above tests were then performed sequentially, and the changes in the contact force readings were considered as a signature of that Surgical Variable.

In an actual surgical case, having obtained readings from the Surgical Tests, the data will be compared with the signatures of the Surgical Variables. This will then identify the Variable which needed correction. The Surgical Tests will be repeated and the readings should be closer to balanced. Further correction of another Variable is carried out if necessary. In early clinical cases, it was found that this method allowed for identification of how to reach a balanced state, and achieved soft tissue balancing in a quantitative way.