Summary Statement. A porcine model using Yucatan minipigs was found to be very promising for the investigation of healing around transcutaneous osseointegrated implants. Pigs demonstrated surprising agility and adaptability including the ability to ambulate on three legs during the immediate postoperative period. Introduction. Previous non weight-bearing and weight-bearing caprine, canine and ovine models have evaluated design, material, and biological coating variations in an attempt to improve the wound healing and skin-implant seal around transcutaneous osseointegrated implants. Although these models have primarily been used as a window into the application of transcutaneous osseointegrated implants in humans, some important model characteristics affecting wound healing and infection have been missing including: 1) replication of the physiological tissue response, and 2) availability of a transcutaneous site with sufficient soft tissue coverage. Pig skin, like human, is relatively hairless, tightly attached to the subcutaneous tissue, vascularised by a cutaneous blood supply, and healed by means of epithelialization. Swine have been extensively utilised for superficial and deep wound healing studies and can offer ample soft tissue coverage following a lower limb amputation. Development of a porcine model is important for continued understanding and improvement of weight-bearing transcutaneous osseointegration. Methods. Two male Yucatan mini-pigs (9 months, 36kg) were fit with transcutaneous osseointegrated prostheses using a single-stage transtibial amputation and prosthesis implantation procedure. The endo-prosthesis consisted of a cylindrical intraosseous threaded section and a smooth transcutaneous section. The transcutaneous sections were smooth to promote epithelialization and deter direct skin-implant adhesion. The implants were custom manufactured from medical grade Ti-6Al-4V alloy. The exo-prosthesis, consisting of an adjustable length leg and foot, was attached by clamp to the supercutaneous portion of the implant following either one or two days of sling constraint to limit initial weight-bearing. Various exo-prosthesis designs and configurations were trialed. The animals’ behavior and gait were closely observed. Weight-bearing was monitored using a force plate. At 5 and 8 weeks, clinical, microbiological, and histological data were examined to assess wound healing and infection at the skin-bone-implant interface. Results. The pigs demonstrated surprising agility and adaptability. They were able to successfully ambulate on three legs during the post-op period before weight-bearing was permitted. They adapted quickly to changes in exo-prosthesis design, position, and length. Although bacterial colonization was verified, neither of the animals exhibited clinical signs of infection over the respective eight and five week studies. Histological results indicated that there was no skin to implant adhesion but that epithelial growth was progressing towards the implant in one animal. Healing of the transcutaneous wound site showed substantial progress but a definitive skin seal was non-existent at the eight week time point. Discussion/Conclusion. This is likely the first animal model developed, having soft tissue characteristics similar to those found in humans, in which an axially-loaded, weight-bearing implant was successfully used. Results indicated that this porcine model offers many advantages over previous models for the development, evaluation, and comparison of the various techniques being advocated to achieve successful transcutaneous osseointegration in humans. The Yucatan miniature pig's ability to ambulate on three legs during the immediate post-operative period and quickly adjust to changes in the exo-prosthesis design, coupled with their physiological similarity to humans, makes them a valuable model for future studies

Introduction. It is well known that blood flow is a critical key component of fracture repair. Previously, we demonstrated that transcutaneous application of CO2 increased blood flow in the human body. To date, there has been no report investigating the effect of the carbonated therapy on fracture repair. Hypothesis. We hypothesized that the transcutaneous application of CO2 to fracture site would accelerate fracture repair. Materials & Methods. A closed femoral shaft fracture was produced in rats. Transcutaneous CO2 absorption enhancing hydrogel and CO2 adaptor that sealed the body surface and retained the gas inside were used for CO2 treatment. Rats without CO2 treatment served as control. Radiographic, biomechanical and histological analysis was performed to assess the fracture repair. Gene expression of chondrogenic, hypertrophic, osteogenic and angiogenic markers was measured by real-time PCR at 1, 2, 3, and 4 weeks post-fracture. Results. Union rate, biomechanical properties, and gene expression of chondrogenic, hypertrophic, osteogenic and angiogenic markers was significantly higher in CO2 group compared to control group. Histological evaluation demonstrated that enchondral ossification was promoted in CO2 group. Discussion & Conclusions. Our study indicate that transcutaneous application of CO2 accelerates fracture repair via acceleration of endochondral ossification and vascularization, and may become a novel and useful therapy for promoting fracture repair

Aims. The aim of this study was to describe implant and patient-reported outcome in patients with a unilateral transfemoral amputation (TFA) treated with a bone-anchored, transcutaneous prosthesis. Methods. In this cohort study, all patients with a unilateral TFA treated with the Osseointegrated Prostheses for the Rehabilitation of Amputees (OPRA) implant system in Sahlgrenska University Hospital, Gothenburg, Sweden, between January 1999 and December 2017 were included. The cohort comprised 111 patients (78 male (70%)), with a mean age 45 years (17 to 70). The main reason for amputation was trauma in 75 (68%) and tumours in 23 (21%). Patients answered the Questionnaire for Persons with Transfemoral Amputation (Q-TFA) before treatment and at two, five, seven, ten, and 15 years’ follow-up. A prosthetic activity grade was assigned to each patient at each timepoint. All mechanical complications, defined as fracture, bending, or wear to any part of the implant system resulting in removal or change, were recorded. Results. The Q-TFA scores at two, five, seven, and ten years showed significantly more prosthetic use, better mobility, fewer problems, and an improved global situation, compared with baseline. The survival rate of the osseointegrated implant part (the fixture) was 89% and 72% after seven and 15 years, respectively. A total of 61 patients (55%) had mechanical complications (mean 3.3 (SD 5.76)), resulting in exchange of the percutaneous implant parts. There was a positive relationship between a higher activity grade and the number of mechanical complications. Conclusion. Compared with before treatment, the patient-reported outcome was significantly better and remained so over time. Although osseointegration and the ability to transfer loads over a 15-year period have been demonstrated, a large number of mechanical failures in the external implant parts were found. Since these were related to higher activity, restrictions in activity and improvements to the mechanical properties of the implant system are required. Cite this article: Bone Joint J 2020;102-B(1):55–63

Conventional amputation prostheses rely on the attachment of the socket to the stump, which may lead to soft-tissue complications. Intraosseous transcutaneous amputation prostheses (ITAPs) allow direct loading of the skeleton, but their success is limited by infection resulting from breaching of the skin at the interface with the implant. Keratinocytes provide the skin’s primary barrier function, while hemidesmosomes mediate their attachment to natural ITAP analogues. Keratinocytes must attach directly to the surface of the implant. We have assessed the proliferation, morphology and attachment of keratinocytes to four titaniumalloy surfaces in order to determine the optimal topography in vitro. We used immunolocalisation of adhesion complex components, scanning electron microscopy and transmission electron microscopy to assess cell parameters. We have shown that the proliferation, morphology and attachment of keratinocytes are affected by the surface topography of the biomaterials used to support their growth. Smoother surfaces improved adhesion. We postulate that a smooth topography at the point of epithelium-ITAP contact could increase attachment in vivo, producing an effective barrier of infection

Aim: We have carried out a prospective study to compare duplex ultrasonography and transcutaneous oxygen tension as predictors of wound healing after knee arthroplasty. Methods and Materials: 53 patients were included in the study. All underwent pre-operative duplex scans of their lower limbs. In addition, transcutaneous oxygen tension measurements were made adjacent to the proposed incision pre-operatively and on days 1, 3 and 7 post knee arthroplasty. Wound healing was assessed using the ASEPSIS wound score. Results: 4 wounds had evidence of delayed wound healing. Duplex ultrasonography was a poor predictor of such problems; however there was a significant correlation between pre-operative transcutaneous oxygen tension and post-operative wound scores. Conclusion: Pre-operative transcutaneous oxygen tension measurement is a better predictor of wound healing after knee replacement surgery than duplex ultrasonograph, and may be a useful adjunct to the investigation of patients at risk of wound problems post knee arthroplasty

The transcutaneous oxygen pressure (tcPO2) was measured by a polarographic technique in the legs of 161 volunteers and compared with the levels found in 62 patients with ischaemic skin due to peripheral vascular disease. The results show that the tcPO2 was related to the degree of ischaemia and, in many cases, was a more accurate guide to the viability of the skin than clinical assessment. Measurement of the transcutaneous oxygen pressure in the leg at the site of amputation in 24 patients with peripheral vascular disease showed that a preoperative level greater than 40 millimetres of mercury at an electrode temperature of 44 degrees Celsius was necessary for the skin of the stump to heal. The technique is simple, non-invasive and reliable. The tcPO2 accurately reflects the physiological and pathological changes in the circulation of the skin. It has potential in many fields of surgery where careful assessment of the viability of the skin is necessary

Intraosseous Transcutaneous Amputation Prosthesis (ITAP) is a new generation of limb replacements that can provide to amputees, an alternative solution to the main problems caused by the most common used external prosthesis such as pressure sores, infections and unnatural gait. ITAP is designed as one pylon osteointegrated into the bone and protruding through the skin, allowing both the mechanical forces to be directly transferred to the skeleton and the external skin being free from frictions and infections. The skin attachment to the implant is fundamental for the success of the ITAP, as it prevents the implant to move and consequently fail. In this study we wanted to test if cell viability and attachment was improved using TiO2 nanotubes. Human keratinocytes and human dermal fibroblasts were seeded for three days on TiO2 nanotubes with different sizes (18–30nm, 40–60nm and 60–110nm), compared with controls (smooth titanium) and tested for viability and attachment. A Mann-Whitney U test was used to compare groups where p values < 0.05 were considered significant. The results showed that the viability and cell attachment for keratinocytes were significantly higher after three days on controls comparing with all nanotubes (p=0.02), while attachment was higher on bigger nanotubes and controls. Cell viability for fibroblasts was significantly higher on nanotubes between 40 and 110nm comparing with smaller size and controls (p=0.03), while investigation of cell attachment is ongoing. From these early results, we can say that TiO2 nanotubes can improve the soft tissue attachment on ITAP. Further in-vitro and ex-vivo experiments on cell attachment will be carried out

Introduction and Objective. Knee osteoarthritis (KOA) is a frequent disease for which therapeutic possibilities are limited. In current recommendations, the first-line analgesic is acetaminophen. However, low efficacy of acetaminophen, frequently leads to the use of weak opioids (WO) despite their poor tolerance, especially in elderly patients. The primary objective was to compare the analgesic efficacy and safety of a new wearable transcutaneous electrical nerve stimulation (W-TENS) to weak opioids (WO) in the treatment of moderate to severe, nociceptive, chronic pain in knee osteoarthritis patients. Materials and Methods. ArthroTENS study is a phase 3, non-inferiority, multicentric, prospective, randomized, single-blinded for primary efficacy outcome, controlled, in 2-parallel groups, clinical study comparing W-TENS versus WO over a 3-month controlled period with an additional, optional, non-controlled, 3-month follow-up for patients in W-TENS group. The co-primary outcome was KOA pain intensity (PI) at month 3 and the number of adverse events (AEs) over 3 months. Results. The non-inferiority of W-TENS was demonstrated in both the PP and ITT populations. At M3, PI in PP population was 3.87 (2.12) compared to 4.66 (2.37) (delta: −0.79 (0.44); 95% CI (−1.65; 0.08)) in W-TENS and WO groups, respectively. Since the absolute value of the 95% CI of the between-treatments mean PI difference [−1.71, – 0.12] was above 0 in ITT set, the planned superiority analysis was performed, demonstrating that W-TENS was significantly superior to WO at M3 (P=0.0124). At M1 and M3, the W-TENS group reached the absolute minimal clinically important difference (MCID) for an analgesic (1.8 (2.1) and 2.1 (2.3), respectively), corresponding to a 20 mm reduction in PI (interquartile range: 15–30) on a 0–100 mm visual analogic scale – i.e. 2 points on a numerical rating scale – which equates to “much better”. Conversely, in the WO group, a 0.5 (1.8) and a 1.1 (2.1) reduction in PI were observed at M1 and M3, respectively, while a 1-point reduction in PI is required to be considered as a “slightly better” improvement. In WO group, AEs were the common systemic AEs reported with WO (nausea, constipation, drowsiness, dizziness, pruritus, vomiting, dry mouth). AEs in W-TENS group were local, such as local cutaneous reaction (erythema). Thirty-nine (70.9%) patients wished to extend W-TENS treatment for 3 additional months. Only one patient discontinued this additional period and results were maintained at M6. Conclusions. W-TENS was more effective and better tolerated than WO in the treatment of nociceptive KOA chronic pain and could represent an interesting non-pharmacological alternative to WO

Aims. The Intraosseous Transcutaneous Amputation Prosthesis (ITAP) may improve quality of life for amputees by avoiding soft-tissue complications associated with socket prostheses and by improving sensory feedback and function. It relies on the formation of a seal between the soft tissues and the implant and currently has a flange with drilled holes to promote dermal attachment. Despite this, infection remains a significant risk. This study explored alternative strategies to enhance soft-tissue integration. Materials and Methods. The effect of ITAP pins with a fully porous titanium alloy flange with interconnected pores on soft-tissue integration was investigated. The flanges were coated with fibronectin-functionalised hydroxyapatite and silver coatings, which have been shown to have an antibacterial effect, while also promoting viable fibroblast growth in vitro. The ITAP pins were implanted along the length of ovine tibias, and histological assessment was undertaken four weeks post-operatively. Results. The porous titanium alloy flange reduced epithelial downgrowth and increased soft-tissue integration compared with the current drilled flange. The addition of coatings did not enhance these effects. Conclusion. These results indicate that a fully porous titanium alloy flange has the potential to increase the soft-tissue seal around ITAP and reduce susceptibility to infection compared with the current design. Cite this article: Bone Joint J 2017;99-B:393–400

Background: Osseointegrated amputation prostheses avoid soft tissue complications associated with traditional socket prostheses. Forces are transmitted directly to the skeleton resulting in improved function. However, approximately 50% of transcutaneous implants become infected due to the lack of a successful skin-implant seal. Intraosseous Transcutaneous Amputation Prostheses (ITAP) are designed to integrate with the skin preventing epithelial downgrowth and infection. Fibronectin adsorption enhances fibroblast adhesion in vitro; however, in vivo, fibronectin becomes desorbed from the implant surface. Covalent attachment of fibronectin by silanisation has been shown to be durable in vitro. The silanisation process for fibronectin includes a stage of passivation with sulphuric acid which alters surface characteristics. Aims: The aim of this study was to determine if in vitro fibroblast adhesion to silanised fibronectin (SiFn) titanium alloy could be improved by omitting or reducing the length of time of passivation. The study also assessed the effects of SiFn on dermal attachment in vivo comparing the results with adsorbed fibronectin substrates and with uncoated controls. Methods: Scanning electron microscopy, Ra profilometry and contact angle measurement (n=6) were used for topographical characterization of surfaces. Anti-vinculin antibodies were used to immunolocalize fibroblast adhesion sites after 24 hours. The morphology of fibroblasts on each surface was evaluated using scanning electron microscopy. Subcutaneous plates were implanted onto the tibiae of an ovine model (n=3) in order to evaluate the performance of the modified SiFn surface in vivo. Hydroxyapatite (HA) and adsorption of fibronectin to HA (HAFn) were also tested because HA coatings are currently applied to the dermal section of ITAP in clinical trials. After four weeks, a histological assessment of the percentage of soft-tissue attachment and cell alignment relative to the implant was performed. Results: Passivation produced rougher, more hydrophobic surfaces with numerous microcracks and was associated with poorer fibroblast adhesion and spreading than un-passivated controls in vitro. SiFn with passivation resulted in poorer cell adhesion than SiFn without passivation. Reducing the time period for passivation did not reduce the detrimental effects of passivation In vivo, HAFn and SiFn resulted in higher median values for soft-tissue attachment than simple adsorption of fibronectin; however, the differences were not statistically significant. Cell alignment was significantly different for HAFn and SiFn compared with controls (p< 0.05), with cells on the fibro-nectin treated surfaces orientated more perpendicular to the implant surface. Conclusion: Omission of passivation improves fibro-blast adhesion to SiFn surfaces in vitro. Coating with fibronectin either by silanisation onto titanium alloy or by adsorption onto HA surfaces affected the orientation of cells in vivo, implying that tissue attachment was enhanced. A time course may be of value to determine if fibronectin coatings are lost over time in vivo

We studied the effect of transcutaneous electrical nerve stimulation (TENS) on stump healing and postoperative and late phantom pain after major amputations of the lower limb. A total of 51 patients were randomised to one of three postoperative treatment regimens: sham TENS and chlorpromazine medication, sham TENS only, and active low frequency TENS. There were fewer re-amputations and more rapid stump healing among below-knee amputees who had received active TENS. Sham TENS had a considerable placebo effect on pain. There were, however, no significant differences in the analgesic requirements or reported prevalence of phantom pain between the groups during the first four weeks. The prevalence of phantom pain after active TENS was significantly lower after four months but not after more than one year

Infection is the primary failure modality for transcutaneous implants because the skin breach provides a route for pathogens to enter the body. Intraosseous transcutaneous amputation prostheses (ITAP) are being developed to overcome this problem by creating a seal at the skin-implant interface to prevent bacterial invasion. Oral gingival epithelial cell adhesion creates an infection free seal around dental implants; however this has yet to be demonstrated outside the oral environment. All epithelial cells attach via hemidesmosomes (HD) and focal adhesions (FA) and their expression is an indicator of adhesion efficiency. The aim of this study was to compare epidermal keratinocyte with oral gingival epithelial cell adhesion on titanium alloy in vitro to determine whether these two cell types differ in their speed and strength of adhesion. It was hypothesised that oral gingival epithelial cells attach to titanium alloy earlier than epidermal keratinocytes; with greater expression of hemidesmosomes and focal adhesions. Human oral gingival epithelial cell (HGEP) and primary human epidermal keratinocyte (HPEK) adhesion to titanium alloy, was assessed at 4, 24, 48 and 72 hrs. Adhesion was measured by the number of FAs per unit cell area and expression of HDs using a semi-quantitative scale. At 4 and 24hrs, there was a significant increase in vinculin marker expression per unit cell area of 4.3 and 4.7 times in HGEP compared with HPEK (p=0.000). At 48 and 72hrs there were no significant differences. HD expression was significantly greater in HGEP at 4 and 24hrs (p=0.002) compared with HPEK. Up-regulation of HD expression in HPEK lagged that of HGEP until 48hrs, after which no significant differences were observed. This study has demonstrated that oral gingival cells up-regulate both focal adhesion and hemidesmosome expression at earlier time points compared with epidermal keratinocytes. Expression of hemidesmosomes lags that of focal adhesions, suggesting that focal adhesion formation is a prerequisite for hemidesmosome assembly. We postulate that early attachment of oral gingival epithelial cells to dental implant biomaterials may be responsible for the formation of an infection-free seal

The predictive value of the pedal transcutaneous oxygen tension (tcPO2) and of the distal systolic blood pressure (SBP) in forecasting the necessity for later amputation has been studied in 26 patients suffering from severe chronic ischaemia of the lower limbs. In all these patients vascular surgery had failed or not been possible, and they were threatened by amputation; they suffered from trophic lesions, or pain at rest, or both. The great toe SBP averaged 10 mmHg (range 0 to 60 mmHg) and the pedal tcPO2 10 mmHg (range 2 to 45 mmHg). After six minutes of oxygen inhalation there was an increase in pedal tcPO2 of 9 mmHg (0 to 50 mmHg). After a follow-up period averaging 7 months (range 10 days to 13 months), 13 patients underwent an amputation and nine (five of whom had been amputated) died. The great toe SBP in the patients who required amputation was initially lower than in those who did not. The pedal tcPO2 also was lower in amputated than in non-amputated patients. There was no amputation in the group showing an increase of at least 10 mmHg after six minutes of oxygen inhalation; and conversely, all patients in whom the pedal tcPO2 increased less than 10 mmHg were amputated. Thus increase in the pedal tcPO2 after oxygen inhalation appears the best criterion for estimating the prognosis of severely ischaemic limbs

A consecutive series of 31 displaced fractures of the proximal humerus were randomly selected for treatment either by closed manipulation or by transcutaneous reduction and external fixation. Follow-up assessed the quality of reduction and healing as well as the functional outcome. The external fixation method gave better reduction, safer healing and superior function

Traditional socket prosthesis (TSP) rehabilitation for amputees is associated with substantial dissatisfaction due to poor mobility and pain from soft tissue squeezing. Osseointegration (OI), eliminates skin compression and prosthesis fit issues, providing superior mobility and quality of life (QOL) for most amputees. The potential for OI to benefit patients with exceptionally poor mobility is understudied. To address this knowledge gap, this project investigated the mobility and QOL changes.

A retrospective review was performed to identify transfemoral amputees who presented with wheelchair-bound mobility (K0) and had at least five years of post-osseointegration follow-up. Outcome measures included changes in mobility (K-level, daily prosthesis wear hours, Timed Up and Go (TUG), 6 minute walk test (6MWT)) and QOL (Questionnaire for persons with a Transfemoral Amputation (QTFA); Short Form Health Survey 36 (SF36). Adverse events recorded included debridement for infection, implant revision surgery, fractures, and implant failures.

9 patients with mean age 48.2±7.7 (range 34-59) years were included. The proportion of patients achieving K-level >2 improved from 0/9=0% to [9/9=100%], p<0.001. The 6MWT improved from 0±0 to 320.65±57 meters (p<0.001). The TUG improved from incapable to 10.68±2.7 seconds (p<0.001). Statistically significant QOL metrics included QTFA global score (33.33±31 vs 68.52±21, p=0.039), SF36 physical component score (30.03±6.3 vs 42.34±12, p=0.023) and the SF36 mental component score (47.89±8.8 vs 51.95±10.4, p=0.332). Six patients required operative intervention to address complications. Five developed infections: three had debridement, and 2 required implant removal and reimplantation.

Osseointegration does confer significant sustained mobility and quality of life improvement for wheelchair bound transfemoral amputees. All 9 K0 patients had statistically improved mobility and QOL after osseointegrated reconstruction. This supports osseointegration as an effective rapid and long-term rehabilitation alternative for patients who have the neurologic and muscular capacity to walk but are unable due to issues related to their TSP.

In 42 amputations (28 below-knee and 14 above-knee), healing of the stump was found to correlate with the pre-operative transcutaneous oxygen pressure (tcPO2) measured at the planned site of incision. Of 31 patients with a tcPO2 of 30 mmHg or more, 27 healed primarily, three had delayed healing and one failed to heal; of seven patients with values between 20 and 30 mmHg three healed primarily and four had delayed healing; and all four patients with a value below 20 mmHg had stumps which failed to heal and needed reamputation. It is concluded that a tcPO2 of 20 mmHg or more at the intended site of amputation indicates that the wound will heal

To try and aid the formation of a soft tissue seal to promote dermal and epidermal attachment to Intraosseous Transcutaneous Amputation Prostheses we compared the effect of titanium surfaces functionalised with fibronectin (fn) or YRGD peptide sequences on human dermal cell (HDF) attachment. We hypothesise that YRGD and fn coatings will significantly increase HDF attachment to titanium alloy substrates. Titanium alloy 10mm discs were polished and acted as control substrates, functionalised surfaces had YRGD or fn adsorbed or silanised onto the polished surface. HDFs were seeded at 10,000/disc and cultured for 1, 4, 24 and 96 hours, fixed and fluorescent immnolocalisation for vinculin was performed. Individual vinculin markers were counted and density calculated as a measure of cell attachment. All assays were performed in triplicate and data were analysed in SPSS 19.0 and results were considered significant at the 0.05 level. Results showed an up-regulation of Focal adhesion density (FA) against controls at all time-points (excluding ad-fn at 4 hours, p=0.057), p values < 0.05, the use of functionalised titanium surfaces may lead to long-term clinical success of ITAP. We have shown a significant positive effect on cell attachment when a synthetic peptide sequence is used. Using synthetic peptide sequence may also be more beneficial from a regulatory stand-point compared with using isolated proteins

Introduction. Following amputation, residual stumps used to attach the external prostheses can be associated with sores, infection and skin necrosis. These problems could be overcome by off loading the soft tissues. Intraosseous transcutaneous amputation prostheses (ITAP) attach external implants directly to residual bone reducing these complications. However, a tight seal at the skin implant interface is crucial in preventing epithelial down-growth and infection. Fibronectin (Fn) and laminin 332 (Ln), enhance early cell growth and adhesion of keratinocytes. Silanization to titanium alloy (Ti) allows these proteins to bond to the metal directly. We hypothesize that silanized dual coatings of fibronectin and laminin (SiFnLn) will be more durable than absorbed proteins and that keratinocyte adhesion will be increased compared with Ti controls and single silanized proteins. Methods. 10 mm diameter Ti alloy discs were polished, sterilized and silanized. The kinetics of silanized single and dual protein coating attachment onto titanium alloy was quantified using radio-labelled Fn(125I-Fn) and Ln(125I-Ln). Coating durability was assessed when soaked in fetal calf serum (FCS) for 0, 1, 24, 48, 72hrs. Data was compared to un-silanized Ti discs with the same amount of adsorbed proteins. In order to study cell attachment 20 × 103 keratinocytes were seeded on the discs (n = 6): silanized (Si), silanized fibronectin (SiFn), silanized laminin (SiLn), silanized dual coating (SiFnLn) for 1, 4 and 24hrs. Adhesion of cells was assessed using mouse vinculin antibody for 2hrs and alexafluor for 1hr which stains focal adhesions responsible for attaching cells to surfaces. Axiovision Image Analysis software was used to measure cell area, vinculin markers per cell unit and per unit cell area on 15 cells per disc. Data was analysed in SPSS and significance was assumed at the 0.05 level. Results. Silanized dual coatings bonded to Ti alloy in significantly larger quantities compared with adsorbed coatings (all p values < 0.05). When proteins were combined on silanized discs the same amount of each protein was attached as when used as a single coating (i.e. non competitive binding). Keratinocytes cultured on silanized dual coatings were significantly larger, produced more vinculin markers per unit cell and per cell area compared with single coatings at all time points. Conclusion. This study has demonstrated that silanized using dual proteins on Ti alloy enhances early keratinocyte growth and attachment in vitro. It also shows that there is non-competitive binding of laminin to Ti alloys in presence of fibronectin. This may lead to improved epidermal attachment to ITAP creating a tight seal at the implant interface, which will prevent migration of the epithelium and subsequent infection in vivo

Patients with above knee amputation (AKA) often experience poor socket fit exacerbated by minor weight changes, sweating, and skin problems. A transcutaneous, press-fit distal femoral intra-medullary device was designed in 1999, such that the distal external aspect serves as a hard point for AKA prosthesis attachment. The implant is placed in a retrograde fashion, followed 6-8 weeks later by stomatisation and connected via direct extention to an AKA prosthesis. Thirty-seven patients with 39 limbs (30 males, 7 females) underwent two-stage prosthesis implantation with the Endo-Exo Femurprosthesis (EEFP) in Germany between 1999 and January 2008. Their indications for surgery were persistent AKA prosthesis socket difficulties with absence of major comorbid physical or mental illnesses. The patients were followed clinically and radiographically for a minimum of 2 years. Assessments included patient satisfaction ratings, functional surveys, pain scores, and oxygen consumption. Fifty-four percent of patients needed at least one revision (20/37); 80% were minor (16/20) and 20% were major (4/20). Most of the minor revisions were due to soft tissue stomal irritation and occurred prior to a design change in the prosthesis. 2 patients sustained traumatic, peri-trochanteric fractures that were treated operatively proximal to the implant, with retention of the implant. 4 implants were explanted due to infection or prosthesis fracture and 2 of these (50%) were later reimplanted successfully. Overall, 94.9% (37/39) limbs had ultimate EEFP implant success. All functional assessments showed statistically significant improvement over baseline except oxygen consumption, which trended toward improvement. This procedure demonstrated a high degree of functional improvement for the majority of AKA patients treated. Despite an initially high revision rate, the EEFP prosthesis achieves an extremely high rate of successful reconstruction for trans-femoral amputees when more traditional options have failed and therefore warrants further scientific study

The success of long-term transcutaneous implants depends on dermal attachment to prevent downgrowth of the epithelium and infection. Hydroxyapatite (HA) coatings and fibronectin (Fn) have independently been shown to regulate fibroblast activity and improve attachment. In an attempt to enhance this phenomenon we adsorbed Fn onto HA-coated substrates. Our study was designed to test the hypothesis that adsorption of Fn onto HA produces a surface that will increase the attachment of dermal fibroblasts better than HA alone or titanium alloy controls. . Iodinated Fn was used to investigate the durability of the protein coating and a bioassay using human dermal fibroblasts was performed to assess the effects of the coating on cell attachment. Cell attachment data were compared with those for HA alone and titanium alloy controls at one, four and 24 hours. Protein attachment peaked within one hour of incubation and the maximum binding efficiency was achieved with an initial droplet of 1000 ng. We showed that after 24 hours one-fifth of the initial Fn coating remained on the substrates, and this resulted in a significant, three-, four-, and sevenfold increase in dermal fibroblast attachment strength compared to uncoated controls at one, four and 24 hours, respectively

The December 2022 Research Roundup. 360. looks at: Halicin is effective against Staphylococcus aureus biofilms in vitro; Synovial fluid and serum neutrophil-to-lymphocyte ratio: useful in septic arthritis?; Transcutaneous oximetry and wound healing; Orthopaedic surgery causes gut microbiome dysbiosis and intestinal barrier dysfunction; Mortality in alcohol-related cirrhosis: a nationwide population-based cohort study; Self-reported resistance training is associated with better bone microarchitecture in vegan people

According to the latest report from the German Arthroplasty Registry, aseptic loosening is the primary cause of implant failure following primary hip arthroplasty. Osteolysis of the proximal femur due to the stress-shielding of the bone by the implant causes loss of fixation of the proximal femoral stem, while the distal stem remains fixed. Removing a fixed stem is a challenging process. Current removal methods rely on manual tools such as chisels, burrs, osteotomes, drills and mills, which pose the risk of bone fracture and cortical perforation. Others such as ultrasound and laser, generate temperatures that could cause thermal injury to the surrounding tissues and bone. It is crucial to develop techniques that preserve the host bone, as its quality after implant removal affects the outcome of a revision surgery. A gentler removal method based on the transcutaneous heating of the implant by induction is proposed. By reaching the glass transition temperature (T. G. ) of the periprosthetic cement, the cement is expected to soften, enabling the implant to be gently pulled out. The in-vivo environment comprises body fluids and elevated temperatures, which deteriorate the inherent mechanical properties of bone cement, including its T. G. We aimed to investigate the effect of fluid absorption on the T. G. (ASTM E2716-09) and Vicat softening temperature (VST) (ISO 306) of Palacos R cement (Heraeus Medical GmbH) when dry and after storage in Ringer's solution for up to 8 weeks. Samples stored in Ringer's solution exhibited lower T. G. and VST than those stored in air. After 8 weeks, the T. G. decreased from 95.2°C to 81.5°C in the Ringer's group, while the VST decreased from 104.4°C to 91.9°C. These findings will be useful in the ultimate goal of this project which is to design an induction-based system for implant removal. Acknowledgements: Funded by the Deutsche Forschungsgemeinschaft (DFG, German Research Foundation) – SFB/TRR-298-SIIRI – Project-ID 426335750

Summary Statement. A novel transcutaneous CO. 2. therapy significantly enhanced the antitumor effectiveness of X-ray irradiation in human MFH xenografts The results strongly suggest that transcutaneous CO. 2. therapy could be a novel therapeutic tool for overcoming radioresistance in human malignancies. Introduction. Hypoxia contributes to tumor radioresistance. In the presence of oxygen, reactive oxygen species (ROS) play crucial roles in cellular apoptosis to irradiation. We previously showed that a novel transcutaneous application of CO. 2. can improve hypoxia and that it induces apoptosis and decreases the expression of HIF-1α in sarcoma. Therefore, we hypothesised that a transcutaneous application of CO. 2. may increase radiosensitivity in sarcoma by improvement of hypoxic condition and increasing ROS production in tumors. The purpose of this study is to examine the effect of transcutaneous application of CO. 2. on radiosensitivity in human malignant fibrous histiocytoma (MFH) cells. Methods. Cells. We used a human MFH cell line, Nara-H in this study. X-ray irradiation. X-ray irradiation was performed at a dose rate of 0.64 to 0.66 Gy/min. Colony formation assay. In vitro cell viability after X-ray irradiation was assessed by colony formation assay. In vivo studies. Nara-H cells were subcutaneously implanted to 24 nude mice which were randomly divided into 4 groups; CO. 2. group, X-ray group, Combination group and Control group. CO. 2. therapy was performed as we previously reported (1, 2). In combination group, mice were treated twice a week by X-ray at 3.2 Gy shortly after CO. 2. therapy for 2 weeks. The changes in body weight and tumor volume were monitored for 14 days in all 4 groups. The implanted tumors were excised at the end of experiment. We also excised tumors on the first day of each treatment in all 4 groups, and examined apoptosis and ROS expression by FACS analysis. The animal experiments were approved by the Animal Committee in our institute. Immunoblot analysis. The protein expression of HIF-1α, ROS-related proteins (p38 and JNK/SAPK), and apoptosis-related proteins (caspase-3 and PARP) were assessed by immunoblot analysis. FACS analysis. DNA fragmentation and ROS production in tumors were assessed by FACS analysis. Statistical analysis. ANOVA with post hoc test to compare for continuous values. All tests were considered significant at p<0.05. Results. Approximately 50% of Nara-H cells survived after a total of 3.2 Gy X-ray irradiation. Tumor volume in combination group was significantly reduced at the end of experiment (47% of that in X-ray group and 28% of that in control group). In Combination group, apoptosis with ROS production markedly increased when compared with those in Control, CO. 2. or X-ray group at 24 hours after treatment. Immunoblot analysis showed that, in combination group, the expression of phospho-p38, phospho-JNK/SPAK, and cleavage of both caspase-3 and PARP were increased compared with other groups, conversely, the expression of HIF-1α was decreased. Discussion/Conclusion. In this study, we demonstrated that the combination therapy showed more significant effects on apoptosis and ROS production through improving hypoxia in MFH cells in vivo. Our findings strongly suggest that the combination therapy of CO. 2. and X-ray could be a novel therapeutic strategy for the treatment of human MFH, and that transcutaneous application of CO. 2. may be one of the best radiosensitisers

Summary. Osseointegrated Amputation Prostheses can be functionalised by both biological augmentation and structural augmentation. These augmentation techniques may aid the formation of a stable skin-implant interface. Introduction. Current clinical options are limited in restoring function to amputees, and are associated with contact dermatitis and infection at the stump-socket interface. Osseointegrated Amputation Prosthesis attempts to solve issues at the stump-socket interface by directly transferring axial load to the prosthesis, via a skin-penetrating abutment. However, development is needed to achieve a seal at the skin-implant interface to limit infection. Fibronectin, an Extracellular Matrix protein, binds to integrins during wound healing, with the RGD tripeptide being part of the recognition sequence for its integrin binding domain. In vitro work has found silanization of RGD to polished titanium discs up regulates fibroblast attachment compared to polished control. Electron Beam Melting can produce porous titanium alloy implants, which may encourage tissue attachment. This study aims to test whether a combination of biological RGD coatings and porous metal manufacturing techniques can encourage the formation of a seal at the skin-implant interface. Materials and Methods. We developed four different augmented transcutaneous devices: Porous, Porous RGD coated, drilled and drilled RGD coated. These were implanted in tibial transcutaneous ovine model, n=6, for a period of 6 months. Following explantation we performed hard grade resin histology to assess soft tissue attachment at the transcutaneous interface. Results. Histological analysis revealed no statistical difference in epithelial downgrowth and epidermal attachment values between the four augmented devices. There were significant increases (p<0.05) in the number of blood vessels and the number of cells in the Porous RGD devices compared with both drilled implant devices. Both Porous and Porous RGD implant groups observed significant increase (p<0.05) in soft tissue infiltration compared with both Drilled implant devices. Discussion. The use of porous structures and RGD coatings increases tissue ingrowth and revascularisation in ITAP devices despite having no effect on epithelial downgrowth and epidermal attachment in a long-term ovine model. There were no detrimental effects in the transcutaneous interface formation observed. These augmentation techniques may prove beneficial in preclinical and clinical developments of transcutaneous osseointegrated devices

Introduction. Advantages of osseointegration have been reported to include improved functional mobility, better osseoperception, improved comfort, reduced pain, better biomechanical alignment and gait, which all lead to a less restricted lifestyle and significantly improved quality of life. A major concern of the Osseointegrated approach lies in the risk of infections occurring from the permanent transcutaneous opening often referred to as the stoma. Materials and Methods. Detailed analysis has been performed on all osseointegration surgeries performed by the Osseointegration Group of Australia and it's affiliates since 2010. All events leading to a re-admission and subsequent re-operation have been identified through hospital operation records and pooled together for meta-analysis. Events identified include: revision of implants, periprosthetic fracture fixation, surgical debridement due to infections, neurectomies and soft- tissue refashioning. Results. Majority of these cases were performed following the single-stage protocol. Among all cases, there were a total of 399 re-operation events recorded which occurred among 163 patients, indicating a high recurrence rate among the same patients. We recorded a total of 112 washouts, 93 neurectomies, 117 soft tissue refashions, 53 implant revisions and 24 periprosthetic fracture fixations. Conclusions. In this study, we have identified several addition possible reasons in which an osseointegration patient may need to be re-admitted into hospital for additional surgery. It was identified that through the implementation of improved surgical techniques and rehabilitation protocols, the rate of several of these re-operation events can be largely reduced, thus improving the overall outcomes of patients undergoing osseointegration surgery

Introduction. Osseointegration has emerged as a promising alternative to rehabilitating with a traditional socket mounted prosthesis. Advantages have been reported to include improved functional mobility, better osseoperception, improved comfort, reduced pain, better biomechanical alignment and better gait, which all lead to a less restricted lifestyle and significantly improved quality of life. A major concern of the Osseointegrated approach lies in the risk of infections occurring from the permanent transcutaneous opening often referred to as the stoma. Several systematic reviews have indicated that the occurrence of minor infections can be quite common, serious complications are reported to be rare. In addition to commonly anticipated complications including fractures, surgical debridements or revisions, we have identified several significant events in which a patient may require to be readmitted and go through additional surgery. The objective of this study is to examine the rate of occurrence and reports on the best management practices of serious complications across a multi-centre review of more than 1000 osseointegration surgeries. Materials & Methods. A detailed analysis has been performed on all osseointegration surgeries performed by the Osseointegration Group of Australia and it's affiliates between since 2010. The majority of surgeries took place in Australia, the United States, the Middle East as well as in Europe. All events leading to a re-admission and subsequent re-operation have been identified through hospital operation records and pooled together for meta-analysis. Events identified include: revision of implants, periprosthetic fracture fixation, surgical debridement due to infections, neurectomies and soft- tissue refashioning. Results. Over 800 surgeries have been identified with a minimum 12-month follow-up time and included in this study. These included tibial, femoral and humeral, radial-ulnar and transpelvic osseointegration cases. The majority of these were performed using a single stage protocol. While general complications such as infection and soft tissue refashioning are common, serious events such as revision and fracture are rare. Interestingly, the rate of debridements and soft-tissue refashions were found to be higher among patients who were operated using a two-stage surgery. Among all cases, there were a total of 399 re-operation events recorded which occurred among 163 patients, indicating a high recurrence rate among the same patients. We recorded a total of 112 washouts, 93 neurectomies, 117 soft tissue refashions, 53 implant revisions and 24 periprosthetic fracture fixations. Conclusions. Many events leading to readmission after the primary surgery may not necessarily be graded as a complication of the osseointegration technique. This study has identified several addition possible reasons in which an osseointegration patient may need to be re-admitted into hospital for additional surgery. It was identified that through the implementation of improved surgical techniques and rehabilitation protocols, the rate of several of these re-operation events can be largely reduced, thus improving the overall outcomes of patients undergoing osseointegration surgery

Introduction. Approximately 2,000 Skeletal transcutaneous osseointegration (STOI) procedures have been performed worldwide as of 2020, more than half of which have been performed by the Osseointegration Group of Australia using a press-fit technique with either ILP or OPL implant designs. Despite the consistently demonstrated clinical benefits, concerns regarding potential complications following STOI have slowed its widespread adoption. As more patients are followed for a longer period of time, longitudinal studies have confirmed complication rates are very acceptable, similar to those of total ankle and total elbow replacements. One of the major risk category is implant removal. The primary goal of this study was to investigate the complications and technical issues associated with transtibial osseointegration implant removal due to any cause. The focus here will be on the press-fit ILP and OPL implants, including the indications for removal and patient outcomes following removal. Materials & Methods. A review of our osseointegration registry between November 2010 and March 2022 was performed. Inclusion criteria were patients who have undergone removal of a transtibial osseointegration implant due to any cause. Selected patients either had a follow-up of at least two years or had their index osseointegration surgery at least two years prior to when the study was performed. Patients who have had osseointegration at other anatomic levels, and patients who underwent simultaneous total knee replacement with transtibial osseointegration were excluded from the registry search. Results. There were a total of 148 transtibial osseointegration procedures performed during the study period, with 97 (65.5%) performed in males and 51 (34.5%) performed in females. The average age at first stage osseointegration procedure is 50.4 years (range 16.8–87.9, SD 14.1). In the study cohort of 22 cases requiring implant removals, 12 (54.5%) were male and 10 (45.5%) were female. The average age at first stage osseointegration procedure in this cohort is 51.3 (range 37.4–82.6, SD 10.7) and average BMI 30.3 (range 21.9–40.9, SD 5.8). Although men comprised the majority of removals, women had a greater relative risk (Fisher exact test p=0.032). The average duration from time of STOI to removal was 2.6 years (range 0.1–6.8, SD 1.9) within this 11.5 year follow-up period. The most frequent indication was infection (54.6%, n=12) followed equally by pain (13.6%, n=3), aseptic loosening (13.6%, n=3) and implant fracture (13.6%, n=3), and lastly failure to integrate (4.6%, n=1). Conclusions. Of the 22 removals, 12 were reimplanted at the same anatomical level (10 were reimplanted within 6 months, 1 within 12 months, and 1 within 24 months). 11 of these cases currently wear their prosthetic legs for more than 13 hours daily. 1 case was recently reimplanted and still completing their loading program. Of the patients who were not reimplanted at the same anatomical level, 1 required proximal amputation with transfemoral osseointegration. 3 patients converted to traditional socket prostheses (TSP) due to pain, and 1 underwent proximal amputation and converted to TSP due to infection. 3 cases are currently awaiting transtibial osseointegration reimplantation, and 1 patient was deceased. 1 patient was lost to follow-up

Introduction: Transcutaneous Amputation Prosthesis (ITAP) is an alternative for transfemoral amputees to conventional stump-socket prostheses which have many problems. These include: poor fit, stump pressure sores, pain, infections and unnatural gait. ITAP aims to overcome these by being osseointegrated into the femoral medulla with a pin protruding through the skin to which the external prosthesis attaches. Thus, the forces normally encountered by the stump soft tissues are now transferred directly to the skeleton. However, the transcutaneous pin produces a route for infection from the external to internal environment. Therefore, a key feature to the success of the ITAP is to produce a biological seal at the transcutaneous interface. Epithelial cells have been shown to attach to dental transcutaneous titanium devices via hemidesmosomes (HD).2 Focal contacts (FC) are also important in cell adhesion and to the underlying substratum.3 We grew human keratinocytes on different titanium surfaces to assess their morphology, ability to proliferate and produce HD and FC. Hypothesis: Surface topography influences keratinocytes morphology and proliferative capacity and expression of HD and FC. Materials and Methods: 4 titanium alloy (Ti6Al4V) surface topographies were used (10mm x 4mm discs): polished, machine finished, sandblasted and hydrofluoric acid etched (HF) and a control – plastic thermanox. Surface roughness profiling of titanium discs were measured (Mitutoyo Surftest SV-400). HaCaT keratinocytes were grown on disc surfaces in wells of culture medium at +37oC, 5% CO2 and analysed at 1, 2, 3 and 4 days. Cells were processed to visualise HD with fluorescence microscopy using antibodies to the 6-integrin and plec-tin. Anti-vinculin antibodies were used to visualise FC. Fluorescein isothiocyanate (FITC) secondary antibodies enabled counting of structures (all product: Sigma-Aldrich, UK). Alamar blue (Serotec, UK) measured cell proliferation and SEM (surface morphology, cell area) and TEM were also performed. Cells grown on polished, machined and thermanox discs supported a regular, confluent layer with many cytoplasmic processes and dividing cells. HF and sandblasted discs grew an irregularly layer with fewer cytoplasmic processes and fewer dividing cells (not quantified). Day 3 TEM revealed HD, FC and desmosomes; cells on polished and thermanox were more closely packed and in layers. Conclusion: Keratinocytes are significantly influenced by titanium surface topography. Smooth polished titanium alloy may be the ideal surface for a transcutaneous pin in the ITAP. Further experiments into isolating favourable biological components needed to encourage keratinocytes to attach onto titanium should be carried out. Results: No significant difference shown in cell proliferation between titanium discs but cells on thermanox grew significantly more (p< 0.05). FC and HD numbers increased on all surfaces (days 1–3); a negative correlation between surface roughness and HD and FC numbers observed (lower Ra values = more HD and FC expressed)

Introduction. Intraosseous transcutaneous amputation prostheses (ITAP) provide an alternative means of attaching artificial limbs for amputees. Conventional stump-socket devices are associated with soft tissue complications including; pressure sores and tissue necrosis. ITAP resolves these problems by attaching the exo-prosthesis transcutaneously to the skeleton. The aim of this study is to increase the attachment of dermal fibroblasts to titanium alloy in vitro. Fibronectin (Fn) and laminin 332 (Ln) enhance early cell growth and adhesion. We hypothesize that silanized dual coatings of fibronectin and laminin (SiFnLn) will be more durable when compared with adsorbed dual coating (AdFnLn), and will enhance early fibroblast growth and adhesion compared to single coatings. Methods. The kinetics of dual single and dual protein coating attachment onto titanium alloy was quantified on silanized 10mm diameter discs using radiolabelled Fn (125I-Fn) and Ln (125I-Ln). Sixty discs were polished, sterilized and silanized. Coating durability was assessed when soaked in fetal calf serum (FCS) for 0, 1, 24, 48 and 72hrs. Data was compared to un-silanized Ti discs with the same coatings. Five thousand human dermal fibroblasts were seeded on discs (n = 6) of Ti polished alone (Pol), Ti with adsorbed fibronectin (AdFn), Ti with adsorbed laminin (AdLn), Ti adsorbed dual coating (AdFnLn), Ti silanized (Si), Ti silanized with fibronectin (SiFn), Ti silanized with laminin (SiLn), Ti silanized with a dual coating (SiFnLn) for 24hrs. In order to measure cell adhesion fibroblasts were fixed, vinculin stained using mouse vinculin antibody and alexa fluor. Axiovision Image Analysis software was used to measure cell area, vinculin focal adhesion markers per cell and per unit cell area. Data was analysed in SPSS and significance was assumed at the 0.05 level. Results. Silanized dual coatings bonded to Ti alloy in significantly larger quantities compared with adsorbed coatings at all time points (all p values < 0.05). Fibroblasts cultured on dual coatings were significantly larger, produced more vinculin markers per cell, and per unit cell area compared with single coatings. Cells on SiFnLn were larger with more numerous vinculin markers per cell, and per unit cell area compared with AdFnLn (p<0.05). Conclusion. This study has demonstrated that covalently bonding both fibronectin and laminin to Ti alloy provides a durable, dual coating that enhances early fibroblast growth and attachment compared with either protein coating alone in vitro. Our study showed that there is non-competitive binding of laminin on Ti surfaces in the presence of fibronectin. Dual coatings may be applied to the skin-penetrating region of transcutaneous devices to improve the skin seal and this may have positive implications for the development of ITAP

A high incidence of complications with wound healing in calcaneum fractures treated with open reduction and internal fixation (25 – 33% of cases) has been reported. In one study 80% of those who had wound complications required surgical treatment of these. Two recent studies have shown that the risk factors for wound complications in this injury are single layered closure, high BMI, extended time between injury and surgery, diabetes, open fractures and smoking. In our unit, out of a small sample of 56 patients undergoing calcaneal fracture fixation, all those who developed wound complications were smokers. Transcutaneous oximetry is a technique that has been used routinely to assess oxygen perfusion in neonates and also sometimes in peripheral vascular disease (PVD). It has seen greater use as a research tool in PVD and orthopaedic surgery, being used to look at oxygenation around wounds to assess different surgical approaches. This study was performed to assess whether a difference in the oxygen perfusion around the ankle joint could be measured in smokers and non-smokers. A transcutaneous oximetry probe was used to assess the tissue oxygen perfusion at the ankle (posterior to lateral malleolus where the incision line would be) and on the chest (just to the side of the sternum). A standardised technique was used for each patient. Patients were chosen who had no lower limb orthopaedic problem or known PVD. The groups were matched in terms of sex and average age. The data was analysed after logarithmic transformation using a two-tailed Students t-test. The average pO2 chest/foot ratio was higher in the non-smokers than smokers but this was not significant (p=0.704). The average ankle pO2 was higher in the non-smokers and this was shown to be significant (p=0.026). Although a small sample, these data suggest that tissue oxygenation around the ankle may be significantly lower in smokers. This would help to explain why they are at increased risk of wound healing complications. This work also demonstrates that transcutaneous oximetry can be a useful tool in orthopaedic research. Tissue oxygenation around other joints could also be assessed in relation to position to discover the optimum position for wound healing

Problems associated with soft tissues of the stump and attachment of prosthetic devices for amputees remains a considerable problem. These problems are associated with the transmission of load through the soft tissues of the stump and difficulty in attaching the prosthetic device. Several devices have an osteointegrated transcutaneous prosthesis attached to the residual bone onto which an exo-prostheses is secured thereby transmitting load directly through the skeleton. Infection of these devices is a key issue. A biomimetic intraosseous transcutaneous device for amputees known as ITAP has been developed which is based on deer antler morphology. We have shown that in deer antlers the dermal and epithelial tissues are tethered by collagen fibres which originate from pores in the bone. In a caprine model where the soft tissue interface of ITAP is porous, dermal and epithelial integration occurs creating a seal and preventing infection. In two clinical veterinary cases an ITAP implant has been successfully used in trans-radial canine amputees. A human trans-humeral amputee who previously could not wear their exo-prosthesis has been treated with ITAP. The surgery was single stage procedure and involved the insertion of an uncemented intramedullary stem into the residual humerus. A porous flange structure positioned adjacent to the dermal tissue which had most of the hypodermis removed was used to promote soft tissue ingrowth. At two years' post-operation the skin seal has been maintained, there has been no incidence of infection, the patient wears their exo-prostheses for over 8 hours a day and has an almost complete range of shoulder motion. The use of ITAP device in selected cases may revolutionise the way amputees are surgically treated, lead to increased activity levels and more normal life styles in these patients

Fracture separation of the distal epiphysis of the tibia constitutes 10% of all epiphyseal fractures occurring in children. We studied 120 cases, which were treated stationary at our Department over the 10 year period between 1990 – 2000. The ratio between boys and girls was 2:1. The average age was 12,5 years (8–15 years). In 96 cases (80%) the injury occurred after a fall on the playground, in 12 cases (10%) after a roadtraffic accident and in 12 cases (10%) after a fall from a height. The average follow up is 7,2 years (2–12 years). According to the Salter-Harris classification 6 cases (5%) were Salter I, 90 cases (80%) were Salter II, 9 cases (9%) were Salter III and 6 cases (5%) were Salter IV. In all cases a closed reduction under general anaesthesia was attempted. If the reduction was succesful a whole leg plaster was applied. If the reduction was unstable a transcutaneous stabilisation or open reduction and internal fixation was performed. If a reduction could not be acchieved open reduction and internal fixation (ORIF) was performed using Kirschner wires or screws. Closed reduction was performed in 94 cases (78,34%), transcutaneous osteosynthesis in 2 cases (1,66%) and ORIF in 24 cases (20%). We conclude that sports and for instance football is the main cause, where this injury occurs. The treatment is mainly conservative and complications are rare, when anatomical reduction is acchieved. The most common complication is angulation resulting from the injury at the epiphyseal plate, for instance varus angulation, which occurs from supination injuries mainly of Salter-Harris type III and IV

Advances in military surgery have led to significant numbers of soldiers surviving with bilateral above knee amputations. Despite advances in prosthetic design and high quality rehabilitation not all amputees succesfully ambulate. Five patients (10 stumps) with persisting socket fit issues were selected for osseointegration (OI) using a transcutaneous prosthesis with press-fit fixation in the residual femur. Prior to surgery all five were primarily/exclusively wheelchair users. Follow up was from 7 to 25 months (mean 12.2). There were no deaths, episodes of sepsis or osteomyelitis. There was one proximal femoral fracture secondary to a fall. One stump required soft tissue refashioning. Cellulitis needing oral antibiotics occurred in four cases. Functional improvement occurred in all cases with all currently primarily prosthetic users, the majority all day users. Three patients are still completing rehabilitation. Six minute walk tests (SMWT) improved by a mean of 20%. Three are now graded mobility SIGAM F (normal gait) and two SIGAM D-b (limited terrain; with one stick). This cohort suggests that OI may have a role in the treatment of military blast amputees. A larger scale clinical evaluation is planned in the UK blast related amputee population to further establish the benefits and risks of this technique

Introduction: Intraosseous Transcutaneous Amputation Prostheses (ITAP) could overcome the problems associated with conventional stump-socket prostheses for amputees (pressure sores, pain, infections and unnatural gait), by attaching the external prosthesis directly to the skeleton via a skin penetrating abutment. Despite this, the skin breach introduces a potential route for infection. For success, a biological seal at the skin-ITAP interface is essential. The protein Laminin-5 (L-5) is a ‘biological glue’, which is integral to epitheial cell adhesion. Covalently bonding L-5 to the ITAP titanium alloy (Ti6Al4V), may enhance the strength of the skin-ITAP interface. Silanisation, a chemical technique that covalently bonds proteins to metals, could be used to bond L-5 to Ti6Al4V. We have assessed the characteristics L-5 silanised Ti6Al4V as a potential substrate for ITAP. Method: To determine the maximum quantity of L-5 that could be silanised to Ti6Al4V, and its relative stability when soaked in foetal calf serum (FCS) over time; polished Ti6Al4V discs were silanised by immersing in aminopropyltriethoxysilane followed by glutaraldehyde. Radiolabelled rat laminin-5-I125 was then added. Discs were immersed in FCS for 4 days (37 C) and analysed at 24 hour intervals in a liquid scintillation counter. Un-silanised discs were used as controls. Results: L-5 was successfully covalently bound to Ti6Al4V. 10ng, 100ng, 250ng and 500ng droplets yielded significantly more silanised L-5 (p< 0.05), but no difference was observed between 750ng and 1000ng. Percentage L-5 covalently bound ranged from 33% and 65%. A small decrease in bound L-5 occurred after 24 hours of FCS soaking (p< 0.05), but subsequent to this no significant reduction was observed for 4 days (p< 0.05). Controls showed a significantly larger reduction after 24 hours (p< 0.05). Conclusion: Covalently bonding L-5 to Ti6Al4V by silanisation can be achieved with predictable results. Large enough quantities can be immobilised to influ-ence cellular function. L-5 silanised to Ti6Al4V remains stable in vitro over time and is not removed. Following the study of cellular interactions with silanised L-5, a stable skin seal may be achieved at the transcutaneous portion of the ITAP

The prevalence of knee osteoarthritis (OA) in The United States is approximately 40 million cases, and this number is expected to rise to 60 million by the year 2020. Multiple non-operative treatment options are available for patients, including bracing. Braces can also be used for “pre-habitation” prior to total knee arthroplasty (TKA), after TKA, after traumatic sports injuries, and in neurologic patients. Although, the AAOS recommendations for brace use for treatment of knee osteoarthritis (OA) are “inconclusive”, recent studies have shown improved functional outcomes with the use of off-loader braces for the treatment of uni-compartmental knee OA. In addition, supplemental modalities such as transcutaneous electrical nerve stimulation (TENS) and neuromuscular electrical stimulation (NMES) have demonstrated improved subjective and functional outcomes. These off-loader braces and supplemental modalities are easy to use, may decrease pain, delay TKA, and improve clinical outcomes following surgery. In addition, they may decrease the use of other costly knee OA treatment options such as pain medications and intra-articular injections

Introduction: Normal limb use in amputees with made to measure external prostheses can be impaired by problems at the stump – socket interface. The development of an Intraosseous Transcutaneous Amputation Prosthesis (ITAP) would overcome the problems by protecting the soft tissues, whilst redistributing high stresses to bone. ITAP creates a breach in the skins protective barrier to infection, hence requires a sufficient soft tissue – implant seal to prevent implant failure. Deer antlers are natural analogues of ITAP, and successfully overcome the problems associated with skin penetrating implants such as infection, marsupilisation and avulsion. In this study, an ITAP device has been developed, with a successful soft tissue – implant interface, based on deer antler morphology. It is hypothesised that sub-epithelial dermal fibroblastic, but not epithelial layer adhesion, is directly responsible for the degree of downgrowth observed around ITAP. Methods: Eleven pairs of deer antler were used to histologically evaluate the interface between the antler and pedicle, and the soft tissue seal around the antler-pedicle structure. The findings were used to develop a titanium alloy (Ti6Al4V) ITAP device in a goat model. Three to five transcutaneous pins were implanted into the medial aspect of the right tibia of skeletally mature female goats. Four implant designs were tested, Machine Finished Straight (MFS), Hydroxyapatite (HA) Coated MFS, Machine Finished Flanged (MFF) and HA Coated MFF. The 70μ thick HA coating was applied to the implant region abutting the sub-epithelium. The implants remained in situ for four weeks after which the histology of the resulting interfaces were analysed qualitatively and quantitatively for degrees of epithelial downgrowth (marsupilisation) and epithelial/sub-epithelial layer attachment to the implant surface. Results: The histology of the deer antler showed there to be an extremely small area of epithelial attachment, with negligible downgrowth, arrested by soft tissue adhesion to the underlying pedicle surface. There was a significant increase in pore size and frequency in the pedicle structure (abutting the soft tissues), compared to the antler proper. The MFS ITAP implants were associated with significantly greater downgrowth and reduced epithelial and sub-epithelial layer attachment compared to all other implant designs. The HA coating, and porous flange structure significantly reduced downgrowth and increased sub-epithelial layer attachment. Regression correlation showed that there is a significant negative correlation between the extent of downgrowth and the degree of sub-epithelial dermal fibroblastic layer attachment observed around ITAP implants (All p values < 0.05). Discussion: Deer antlers successfully overcome the potential problems for ITAP. By artificially recreating some of the aspects of the antler, including layering of porous and bioactive surfaces for tissue adhesion, we have successfully developed an ITAP implant that minimises downgrowth and actively encourages epithelial and sub-epithelial soft tissue adhesion

Introduction: The ‘gold standard’ currently used to assess bone quality is bone mineral density (BMD) measured by Dual Energy X-ray Absorptiometry (DEXA). However BMD accounts for no more than 60 – 70% of bone strength. X-rays are affected primarily by the mineral phase of bone; the organic phase remains essentially invisible. Yet it is known that the material strength and toughness of bone is critically dependent on its organic phase. A Raman spectroscopic technique was used that permitted visualisation of both phases of bone deep to unbroken skin by successfully removing spectral information from the overlying tissues. Hypothesis: Spectral features of both the mineral and organic phases of bone from different murine genotypes can be measured objectively through the unbroken skin using time-resolved Raman spectroscopy. Methods: We used an 800 nm probe laser (1 kHz, 1 ps pulses, focussed to 1 mm diameter) with a synchronised 4 ps optical Kerr gate that had a variable picosecond delay that effectively shuttered out photons from the overlying tissues. We measured bone spectra at a point 2mm above the carpus from two mouse genotypes: wildtype and oim/oim (matched for age, sex and weight) at a typical depth 1.1mm. We then repeated the measurements once the overlying tissues had been carefully removed to expose the bones directly. Oim/oim mice produce only homotrimeric collagen I, (á1(I)3), associated with this change in collagen is a poor mineralisation of the bone tissue, making it an ideal model for a this study. Results: We recorded the main spectral features in both phases of bone and showed that the ratios of spectral bands from the two phases were similar within each genotype, whether measured through the skin or directly from exposed bone. However, there was a significant difference in the same ratios between genotypes associated with a reduced mineralisation in the oim/oim mice; a significant difference that was apparent both directly from bone and through skin. The band associated with CH2 wag of collagen (organic phase) showed a frequency shift between the genotypes. Discussion: Measurements of the spectra and their analysis were similar whether made directly on bone or transcutaneously. We were able to detect changes in mineralisation between genotypes and, unlike measurements of BMD, we showed also changes in collagen. Since the material strength of bone is critically dependent on collagen, this indicates an appreciable advantage of this technique over DEXA. Conclusions: This novel technique allowed objective transcutaneous spectral measurements of bone tissue and was able to distinguish between normal and unhealthy bone tissue. With a laser focussed to 1 mm diameter that was readily moveable, these measurements were specific to that site (2 mm proximal to the carpus). After further optimisation, this technology is likely to improve fracture risk assessments in comparison to the use of DEXA alone, opening opportunities for screening in anticipation of the predicted increase in fragility fractures

Introduction: Tissue engineered scaffolds require vascularization to 1) enhance nutrient exchange and 2) provide cells needed to build new tissue. Cell-seeded scaffolds; bioreactors-- require rapid penetration of vessels or enhanced fluid percolation to keep their contents alive until normal nutrient exchange can be established. Bone fluid flow depends on a pumping system which drives percolation through its own matrix. Recent interest in the pumping mechanism has resulted in bone fluid flow models, which link the pumps to bending of bone by muscle contraction and compression-tension cycles from weight-bearing during locomotion. The present authors have proposed that capillary filtration, the source of the percolating fluid, is sufficiently enhanced by soliton pressure waves in blood driven by the muscle pump during exercise to provide a significant hydraulic pressure component to bone fluid percolating through bone and any bone-implanted scaffold. A proposal and some preliminary results from a pilot project suggesting enhancement of capillary filtration by the muscle pump is presented. Materials and Methods: Optical bone chambers were implanted in adult New Zealand White female rabbits. Chamber construction and implantation were as usual1. At the third week post-op, chamber ends were exposed and weekly intravital microscopy commenced. Transcutaneous electrical stimulation was administered with a ToneATronic® TENS at 85V, 80mA and 2Hz. The stimulator was applied externally over the gastrocnemius muscle. A fluorescence digital image was obtained before 30 minutes of application of transcutaneous electrical nerve stimulation (TENS) after injection of FITC-D70. Blood samples were obtained from an aural vein in the ear opposite that being injected with the fluorescent dye after each injection. Blood concentration of dye was determined with a SPEX Fluoromax-3 spectrofluorometer for both serum (absolute concentration) and whole blood (to detect differences which would make fluorescence in vessels an inaccurate indicator of red blood cell color contamination). For analysis, four vessels were chosen and the average dye concentration profiles before and after 30 minutes of stimulation were obtained. Results: Results are shown in Figure 1. Extravasated dye levels in TENS rabbits were markedly higher than those in controls. Analysis of profiles using an erfc-based diffusion-convection discrimination model2 showed that extravasation was convective. Discussion: These data are consistent with significant contribution to convective percolation of bone fluid through implanted scaffolds by muscle pump-driven extravasating fluid. They do not, however, answer two critical questions: 1) Is the magnitude of this convection a major component of flow through the scaffold? 2) What are the relative contributions of skeletal muscle-generated intravascular pressure solitons and incompressible fluid transmission of bone bending pressure to the convective flow observed? Additional studies with released gastrocnemius muscles are in progress

Aims

To systematically review the efficacy of split tendon transfer surgery on gait-related outcomes for children and adolescents with cerebral palsy (CP) and spastic equinovarus foot deformity.

Development of more effective diagnostic and therapeutic solutions is vital to tackling the growing challenge of bone diseases and disorders in aging societies. Spatially offset Raman spectroscopy (SORS) enables the chemical specificity of conventional Raman spectroscopy to be combined with sub-surface probing. SORS has successfully been applied to transcutaneous investigations of underlying bone and shows great potential to become an in vivo tool for non-invasive diagnosis of various bone conditions. The volume within the complex hierarchical bone tissue probed by SORS depends on the specimen's optical properties. Understanding the actual sampling depth is important to correctly assign detected chemical changes to specific areas in the bone. This study explores the hypothesis that the effective Raman signal recovery from certain depths requires different spatial offsets depending on the bone mineralisation. SORS depth investigations were conducted on three bones with significantly different mineralisation levels. Thin slices (0.6 – 1.0 mm thickness) were cut from deer antler, horse metacarpal and whale tympanic bulla and stacked together (4 – 7 layers; 4.1 – 4.7 mm total thickness). A 0.38 mm thin slice of polytetrafluoroethylene (PTFE) served as reference sample and was inserted in between the layers of stacked bone slices. Raman spectra were acquired at 30 s using 830 nm excitation. A quantitative relation between the SORS offset and the primarily interrogated depth inside the bone was established. Maximum accessible depths at small offset strongly depend on the mineralisation level. Using large spatial offsets of 7 – 9 mm PTFE signal recovery depths of 4.4 – 4.6 mm through cortical bone can be realized with only minor dependence on the bone mineralisation. These findings highlight the potential of SORS for medical diagnostics by enabling the non-invasive detection of bone conditions characterised by chemical alterations several millimetres inside compact bone tissue (e.g. infections, tumours, etc.)

Aims

As an alternative to external fixators, intramedullary lengthening nails (ILNs) can be employed for distraction osteogenesis. While previous studies have demonstrated that typical complications of external devices, such as soft-tissue tethering, and pin site infection can be avoided with ILNs, there is a lack of studies that exclusively investigated tibial distraction osteogenesis with motorized ILNs inserted via an antegrade approach.

Tourniquet use in total knee arthroplasty (TKA) is convenient for the surgeon and provides a bloodless field for expeditious surgery and a dry field for cementation, but can best be described as an orthopaedic tradition. It is logical for complex anatomy of ligament, nerve, and vessel surgery but it may not be necessary for TKA. In one recent randomised trial, the absence of the tourniquet was not found to affect the quality of cement fixation. There are numerous potential downsides to the use of a tourniquet including decrease range of motion, delayed recovery, increased pain, wound complications, micro-emboli, neuropathy, and increased VTE. There are also a number of complications associated with the use of a tourniquet including arterial thrombosis, skin irritation below the tourniquet, post-operative hyperemia, blood loss, less accurate intra-operative assessment, and it complicates intravenous drug administration. Studies of range of motion have shown that when there is a difference noted, the range of motion is consistently better without tourniquet use. When a tourniquet is utilised it has been found to be advantageous to only use the tourniquet for a minimal amount of the case, typically when cementing is performed. Functional strength has also been found to be improved without the use of a tourniquet. In a recent randomised trial, tourniquet use was associated with decreased quad strength at 3 weeks that persisted at 3 months. This was attributed to muscle damage, tourniquet-induced ischemia, and compressive injury. Increased peri-operative pain has also been reported in randomised trials associated with the use of a tourniquet. Edema, swelling, and limb girth issues have also been noted to be associated with tourniquet use. Exsanguinating a limb will result in swelling approximately 10% of the original volume half due to a return of blood, and half due to reactive hyperemia. Longer tourniquet times are also associated with increased wound drainage and more wound hypoxia as measured by transcutaneous oxygen levels. Tourniquet use has also been associated with embolic phenomenon with several times greater risk of large emboli. In one study where quantitative MRI was utilised on both thighs after unilateral total knee replacement with and without a tourniquet, the tourniquet group showed more atrophy with a loss of 20% of the volume compared to the normal side in total knees performed with a tourniquet which also performed clinically worse. There is a small but substantial risk of arterial thrombosis particularly in patients that have atherosclerotic plaque. Ironically there is a risk of increased post-operative blood loss due to the post-tourniquet “blush” as the blood pressure and pain increase hours after a surgical procedure is completed. There is also difficulty in identifying and coagulating posterior and lateral geniculate vessels with the components in place. Utilizing a tourniquet also interferes with intra-operative assessment of patella tracking, range of motion, ligament stability, and gap balancing. Randomised clinical trials have concluded that there is less pain and quicker recovery without the use of a tourniquet. There have also been reports of less swelling, increased range of motion, less analgesic use and better clinical outcome when a tourniquet is not utilised. A meta-analysis of systematic reviews favored not utilizing a tourniquet due to the decrease in complication rate and the improvement in clinical results. While it is standard practice in the US to utilise a tourniquet, the strong consensus of the literature on the subject favors either not using a tourniquet or minimizing the use of a tourniquet for the period of time necessary for a very dry field for cement fixation

Traditionally, arthritis is a disease which generally affects the elderly population. However, the incidence in young patients is well described and is increasing with the ever-growing obese population. Currently, the non-surgical treatment of osteoarthritis consists of corticosteroid injections, hyaluronic acid injections, weight loss, physical therapy, bracing, orthotics, narcotics, and non-steroidal anti-inflammatory drugs (NSAIDS). Oral medications (NSAIDS, tramadol, and opioids) can provide effective pain relief. Improvement with NSAIDs has been reported to be 20% relative to baseline, with better improvements seen with selective cox-2 inhibitors, which also have reduced gastrointestinal and renal toxicity. Additionally, the recent AAOS guidelines strongly recommend using NSAIDs or tramadol for pain relief. Although narcotics are effective analgesics, their use in young arthritic patients can potentially predispose individuals to future opioid dependency, and thus should be used sparingly. The primary purpose of physical therapy is to improve range of motion, strengthen muscles, and improve proprioception. Currently, the AAOS strongly recommends that patients undergo self-management programs, strengthening, low-impact aerobic exercises, and neuromuscular education. Similarly, they moderately recommended that patients with a BMI ≥ 25 undergo weight loss for symptomatic arthritis. Bracing options consist of the following: off-loader braces and transcutaneous nerve stimulation braces. These work to either off-load pressure in the knee or to scramble small nerve pain sensation, respectively. Corticosteroid injections are used to minimise pain and reduce inflammation in the joint associated with arthritis. However, their long-term repetitive use in young patients is not recommended, and current AAOS guidelines are inconclusive on their effectiveness. Additionally, the AAOS guidelines strongly recommend against the use of acupuncture, glucosamine/chondroitin, and hyaluronic acid injections

This review provides a concise outline of the advances made in the care of patients and to the quality of life after a traumatic spinal cord injury (SCI) over the last century. Despite these improvements reversal of the neurological injury is not yet possible. Instead, current treatment is limited to providing symptomatic relief, avoiding secondary insults and preventing additional sequelae. However, with an ever-advancing technology and deeper understanding of the damaged spinal cord, this appears increasingly conceivable. A brief synopsis of the most prominent challenges facing both clinicians and research scientists in developing functional treatments for a progressively complex injury are presented. Moreover, the multiple mechanisms by which damage propagates many months after the original injury requires a multifaceted approach to ameliorate the human spinal cord. We discuss potential methods to protect the spinal cord from damage, and to manipulate the inherent inhibition of the spinal cord to regeneration and repair. Although acute and chronic SCI share common final pathways resulting in cell death and neurological deficits, the underlying putative mechanisms of chronic SCI and the treatments are not covered in this review.

The viability of three incisions for knee arthroplasty were analysed by transcutaneous estimation of the skin oxygen tension. Wound viability was found to be significantly reduced following knee arthroplasty. The lateral wound edge is more hypoxic than the medial, but there were no significant differences between the three incisions

Chevron osteotomy for correction of symptomatic hallux valgus deformity is a widely accepted method. Full weight bearing in regular shoes is not recommended before six weeks after surgery. Low intensity pulsed ultrasound is known to stimulate bone formation leading to more stable callus and faster bony fusion. We performed a randomized, placebo-controlled, double-blinded study on 44 patients (52 feet) who underwent chevron osteotomy to evaluate the influence of daily transcutaneous low intensity pulsed ultrasound (LIPUS) treatment at the site of osteotomy. Follow up at six weeks and one year was done with plain dorsoplantar radiographs, halluxrmetatarsophalangeal-interphalangeal scale and a questionnaire on patient satisfaction. There was no statistical difference concerning all pre- and postoperative clinical features, patient satisfaction and all radiographic measurements (hallux valgus angle, intermetatarsal angle, sesamoid index, metatarsal index) except for the first distal metatarsal articular angle (DMAA). The DMAA showed statistical significant (p=0,046) relapse in the placebo group comparing intraoperative radiographs after correction and fixation (5,2 degrees) and at six weeks follow up (10,6 degrees). Despite potential impact of LIPUS on bone formation we found no clinical evidence for its influence on outcome six weeks and one year after chevron osteotomy for correction of hallux valgus deformity

A new technique for the treatment of displaced fractures of the proximal humerus is described. Twelve fractures in 11 patients were managed by transcutaneous reduction using a Steinmann pin, and external fixation with a Hoffmann-type neutralising bar connected to two half-pins in the humeral head and three half-pins in the shaft. The pins were removed after four weeks. Two patients sustained redisplacement after a further injury, but in the others reduction was maintained. Two cases of pin-track infection resolved after antibiotics, but delayed union resulted. There were no neurovascular injuries and at follow-up of 6 to 12 months no refractures had been seen. The early functional results were excellent or satisfactory in nine cases

Patients with above knee amputation face many challenges to mobility including difficulty with socket fit and fatigue due to high energy consumption. The aim of the Endo - Exo-Femur Prosthesis is to avoid problems at the interface between the sleeve of the socket-prosthesis and the soft tissue coat of the femur stump which often impedes an inconspicuous and harmonic gait. In 1999 we began using a transcutaneous, press-fit distal femoral intramedullary device whose most distal external aspect serves as a hard point for AKA prosthesis attachment. The bone guided prosthesis enables an advanced gait via osseoperception and leads to a decreased oxygen consumption of the patient. 43 patients were implanted between 1999 and 2009. Four of the 43 required removal:one for intramedullary infection, one due to stem fracture (replaced), and the two for soft tissue infection. The remaining 39 original prostheses remained. Two pertrochanteric fractures occurred, treated with ORIF. Two bilateral procedures were performed. Initially, twenty patients had chronic soft tissue irritation requiring debridement. This completely resolved by changing the connecting components to a highly polished cobalt chrome. All patients reported increased comfort when compared to socket use. The following additional advantages were observed: improved mobility and endurance, improved proprioception, decreased time required for prosthetic donning, lack of concern regarding changing body weight, and the absence of skin irritation. All patients reported an improvement in sense of position and tactile sensation, leading to an improved gait pattern. Subjectively, the EEFP represents a significant improvement in terms of comfort. Since the introduction of high-gloss polished surfaces, soft tissue irritation is largely eliminated. Intramedullary infection has been negligible, as osseointegration seals the medullary cavity. In summary, the EEFP appears to be an attractive option in transfemoral amputees

One hundred and seventy-four consecutive patients with symptoms of derangement of the knee were examined with an arthroscope under local anaesthesia using a continuous pressure-irrigation system. A 0.2 per cent prilocaine-saline solution was used as irrigation fluid. In the first 19 patients the serum level of prilocaine was monitored for six hours after the start of irrigation. Eighteen of the 174 patients had a transcutaneous partial meniscectomy at the same time as the examination. All the patients tolerated the examination well. The distension of the knee produced by the pressure-irrigation system provided a high degree of diagnostic accuracy. The serum levels of prilocaine were low throughout the monitoring period reaching a mean peak value of 0.28 micrograms per millilitre after one hour. There were no adverse side-effects. This technique provides a safe and efficient method to meet the increasing demands of arthroscopic procedures of the knee