Introduction. Despite the positive outcomes in shoulder joint replacements in the last two decades, polyethylene wear debris in metal-on-polyethylene artificial shoulder joints is well-known as a limitation in the long-term survival of shoulder arthroplasties systems. Consequently, there is an interest in the use of novel materials as an alternative to hard bearing surfaces such as pyrolytic carbon layer (PyroCarbon). Materials and Methods. In the present study, the unique Newcastle Shoulder Wear Simulator was used (Smith et al., 2015; Smith et al., 2016) to evaluate the wear behavior of four commercially available PyroCarbon humeral heads 43 mm diameter, articulating against conventional ultra-high molecular weight polyethylene (UHMWPE) glenoid inserts with a radius of curvature of 17.5 mm to form an anatomic total shoulder arthroplasty. A physiological combined cycled “Repeat-motion-load” (RML) (Ramirez-Martinez et al., 2019) obtained from the typical activities of daily life of patients with shoulder implants was applied as a simulator input. A fifth sample of the same size and design was used as a soak control and subjected to dynamic loading without motion during the wear test. The mean volumetric wear rate of PyroCarbon-on-polyethylene was evaluated over 5 million cycles gravimetrically and calculated on the basis of linear regression, as well as the change in surface roughness (S. a. ) of the components using a non-contacting white light profilometer throughout the test. Results. The gravimetric analysis showed a mean volumetric wear rate and standard deviation of 19.3±9.5 mm. 3. /million cycles for the UHMWPE glenoid inserts, whereas PyroCarbon humeral head counterparts did not exhibit a loss in mass throughout the test. The roughness values of the UHMWPE glenoid inserts decreased (P < .001), changing from 296±28 nm to 32±8 nm at the end of the test. In contrast, the PyroCarbon humeral heads did not show a significant change (P = .855) over the 5 million cycles; remained in the same range (21±2 nm to 20±10 nm) with no evidence of wear damage on the surface. Conclusions. This is the first in-vitro shoulder simulator study of a PyroCarbon on UHMWPE articulation. Wear rates were similar to that found to well-proven metal on UHMWPE shoulder arthroplasties. While it was interesting to see that the PyroCarbon did not roughen over the test duration, the lack of an appreciable reduction in wear of the UHMWPE component when articulated with an expensive and complex to manufacture PyroCarbon component likely means there is little clinical cost-benefit in the use of a PyroCarbon on UHMWPE shoulder implant. Declaration of competing interest. Prof. Ian A. Trail received some royalties and research support from Wright Medical Group N.V. None of the other authors, their immediate families, and any research foundation with which they are affiliated did not receive any financial payments or other benefits from any commercial entity related to the subject of this article. For any figures or tables, please contact authors directly

An unconstrained, articulating pyrocarbon cervical total disc replacement (TDR; Rescue, Biomet, US) has been developed. Pyrocarbon is a chemically inert form of carbon with an elastic modulus similar to bone. The long-term durability and wear resistance of pyrocarbon has been demonstrated in other orthopaedic devices. The purpose of this study was two-fold: to compare the wear of identical disc reaplcements fabricated from cobalt chrome (CoCr) and ultrahigh-molecular-weight-polyethylene (UHMWPE) to pyrocarbon and to compare the motion at index and motion segments before and after Rescue TDR. Ten pyrocarbon and three CoCr-UHMWPE TDRs were subjected to 10 million cycles in 20 degrees of flexion–extension with 155N axial load in serum solution at 4.0Hz. One additional CoCr-UHMWPE couple was immersed in serum and loaded to 155 N. TDRs and serum solution were examined at 0, 2.5, 5, 7.5 and 10 million cycles to characterize wear. The surfaces were measured with a coordinate measuring machine prior to and after 10 million cycles. Serum solutions and time controlled serum-only controls were characterized for the quantity of wear debris using particle analysis. Nine cadaver cervical spines were placed through dynamic 2Nm cycles of flexion, extension, and lateral bending. Electromagnetic sensors recorded the motion of each vertebral body in response to applied loads. Total range of motion at the index and adjacent levels were determined for the intact spine and after TDR. There was no significant difference in the pyrocarbon surface geometry after 10 million cycles or in the number of particles generated during testing compared to baseline (p > 0.05). However, CoCr-UHMWPE devices displayed classic patterns of total joint wear. CoCr-UHMWPE wear couples had an initial increase in serum particles, followed by lower particle producing rates that gradually increased. The difference in mean UHMWPE wear particles at each interval was significantly greater than with the pyrocarbon TDR (all p< 0.05). The mean total and dynamic ranges of flexion-extension and lateral bending after implantation of the Rescue TDR at the index level were not statistically significantly different from that of the intact spine (ANOVA: p > 0.05). Similarly, at the superior and inferior adjacent levels, the mean total and dynamic range of flexion-extension and lateral bending after implantation of the Rescue device were not statistically significantly different from the intact spine (ANOVA: p > 0.05)

Introduction and Aims: Unilateral joint destruction in small joints of the hand presents a difficult challenge, particularly in younger patients. Pyrocarbon has a number of properties which may render it more suitable than metal for hemiarthroplasty in selected circumstances. We reviewed the results of our experience with PIP and MCP hemiarthroplasty utilising pyrocarbon implants to evaluate the clinical outcome in each case. Method: Since December 2001, 10 pyrocarbon hemiarthroplasties were implanted in 10 patients. Eight were implanted into the PIP joint and two into the MCP joint. The average patient age was 34.5 years (range 19–65). Nine procedures were for trauma and one for arthrosis. The decision to implant was taken when other reconstructive options were not considered possible and the patient would otherwise have been offered arthrodesis or amputation or total joint arthroplasty. The patients were reviewed clinically to establish their range of motion, pain control and satisfaction with surgery. Radiographic review was undertaken. Results: After an average follow-up of 13 months (range three to 23 months) all joints remain in-situ. The average arc of motion is 50.5 degrees. Average extension was minus eight degrees (range 0–20) and average flexion was 58.5 (range 15–90). There was no evidence of loosening. Erosion of the intact side of the joint was noted in only one patient. One patient was not satisfied with the final outcome. Conclusion: The short-term results of PIP and MCP hemiarthroplasty with a pyrocarbon prosthesis show reasonable promise and this procedure merits further evaluation of its role in the treatment of unilateral joint destruction. It may be preferable to either total joint arthroplasty or fusion, particularly in the younger patient

Pyrocarbon has been used for over 25 years in finger joint replacements. Excellent biocompatibility, material and wear properties make pyrocarbon ideal for an orthopaedic device. Pyrocarbon implants incur significantly less wear to articular cartilage than metal implants. The pyrocarbon implant replacement device (PIR) was developed to treat focal chondral and osteochondral defects of the femoral condyles. The PIR is intended to treat defects not amenable to microfracture or similar regenerative techniques and those for which unicompartmental or total knee arthroplasty is not yet indicated. The purpose of this study was to evaluate the in vivo articular response to the PIR device and compare it to a similar device made from cobaltchromium (CoCr) device. In addition, bone fixation of the PIR device with and without hydroxyapatite (HA) coating was evaluated. Nine adult bred-for-purpose beagles received bilateral 6mm medial condyle full thickness osteochondral defects. One defect was treated with a PIR device and the other an identical CoCr device. In addition, one HA-coated and one non-HA coated PIR device was placed unicortically in the lateral distal femurs of each animal. Three animals each were terminated at 12, 24, and 52 weeks postoperative. Non-decalcified histologic sections of the implanted condyles and decalcified sections of the medial tibia and meniscus were evaluated. The femoral condyle sections were graded using a modified scale of Kirker-Head (2006). Additionally, the bone– implant contact area was quantified. The tibia-meniscus sections were evaluated utilising a modified version of the ICRS Histological Visual Scale (2002). The lateral distal femur implants were mechanically tested in axial push-out to compare the bone-implant interface strength between the HA-coated and non-HA coated PIR devices. The mean histologic grades for the tibia and meniscus were superior for surfaces that articulated against the pyrocarbon PIR device compared to the CoCr device at 12, 24 and 52 weeks. Over time, the mean histologic grades decreased with both materials; however, tibias that articulated with the CoCr device had the lowest mean grade at 52 weeks. There were little difference in bone contact 12 and 24 weeks between the pyrocarbon and the CoCr devices. At 52 weeks, less bone contact was observed compared to 12 and 24 weeks. Mechanical testing demonstrated that the HA-coating imparted a statically significant improvement in interface strength as well as greater direct bone contact to the implant. The results of this study confirm that pyrocarbon provides an ideal surface for an implant that articulates with cartilage of the knee. Although adequate direct bone contact was observed, the addition of HA-coating imparted both superior initial and long term bone fixation. The PIR device is suitable for restoration of focal defects of the knee

Purpose. To analyse the early results of unconstrained pyrocarbon joint replacements in patients with osteo-arthritis of the metacarpo-phalangeal joints. Background. Silicone arthroplasty, as introduced by Swanson in 1962 has remained the most popular procedure to treat arthritis of the metacarpo-phalangeal (MCP) joints. However, despite providing good pain relief, they have shown to demonstrate breakage rates up to 82% at 5 years. This is of great concern in the osteoarthritis (OA) patient group, who tend to be younger and have higher functional demands compared to their rheumatoid counterparts. The newer unconstrained pyrolytic carbon MCP joint prostheses may therefore be more suitable in OA patients whose soft tissue constraints are intact and whose hand function is strong. This study is the first to analyse the results of this implant in a cohort of OA patients only, with prospective data. Methods. 19 primary pyrocarbon metacarpo-phalangeal joint replacements, in 11 patients (5 men and 6 women) were reviewed, with prospective data collection. The diagnosis was primary osteoarthritis in all patients. The mean age at operation was 66.4 years (range 55–82 years). 2 patients underwent concomitant trapiezectomy and one underwent DIPJ fusion. All patients were right hand dominant −75% underwent surgery in their dominant hand. Eleven of the nineteen joints were performed in the index finger, with the remainder in the middle finger. Mean follow up is 22.1 months (range 11–37). Results. At the 3 month post-operative hand therapy assessment, the arc of motion had improved from a mean of 32 degrees to 45 degrees and flexion had improved from a mean of 51 degrees to 66 degrees. Grip strength improved from a mean 20 to 27Kg. DASH scores significantly improved from a mean of 40 to 10 (p=0.01). All patients were satisfied with their outcomes and would have the surgery again. Pre-operative radiographs demonstrated joint narrowing in all patients but no evidence of heterotopic ossification, cystic change or erosions. Post-operatively, there has been no radiographic evidence of joint dislocation, resorption stress-shielding, loosening, migration or heterotopic ossification. There were three intra-operative complications of phalangeal fractures that were immediately treated with a cerclage wire. In one patient there has been a fracture of the proximal phalangeal implant at 14 months which was asymptomatic. One patient has required revision for mal-rotation of the implant leading to loss of index finger supination. Conclusion. Our results demonstrate excellent early results of pyrocarbon MCP joint arthroplasty in OA patients

Background: PIP joint surface replacement has been shown to be effective in the treatment of arthritis. We performed a retrospective review to evaluate the clinical results and functional outcome of pyrocarbon proximal interphalangeal joint replacement, motion preserving and function in selected patients. Method: The patients who underwent pyrocarbon PIP joint arthroplasty by the two senior authors were reviewed. Clinical assessment included range of motion, degree of pain and deformity pre and post operatively. Independent functional scores were collected. Radiographs were reviewed for evidence of loosening, fracture and dislocation. Patient overall satisfaction was assessed. Results: 25 patients had 27 pyrocarbon PIP joint replacements between 2004 and 2008. Of these patients, there were 21 female (84%) and 4 male (16%) with average age of 62.5 (43–78). Indications for surgery were pain and loss of function. The preoperative diagnosis was post traumatic osteoarthritis in 9 (33.3%) and primary osteoarthritis in 18 (66.7%). The average arc of motion preoperatively was 42.3 (5–60), and the average postoperative one was 74.3 (45–100). Pain was relieved in majority of patients. 23 patients (92%) were satisfied completely with the procedure. Pain was relieved in the majority of cases and we had 2 dislocations requiring revision to silicone joint replacement and 2 adhesions/stiffness requiring tenolysis. There were no infections. Conclusion: Our experience of pyrocarbon PIP joint replacement over the 4 years showed this implant is useful for relief of pain and function. A technically demanding procedure, it improves arc of motion, corrects deformity and achieves satisfactory function. We had 7 % revision rate and longer term follow-up is required

The CMI pyrocarbon implant is a unipolar arthroplasty for trapeziometacarpal joint arthritis which is implanted in to the thumb metacarpal. Previous case series have shown these implants provide significant pain relief and good patient satisfaction. We report the first cases of pyrocarbon hemiarthroplasty from Peterborough. Seventeen cases in fifteen patients were retrospectively reviewed. The average patient age was 59.7 years (range 47–72). 7 patients were men and 8 were women. Five were discharged with good outcome at a mean of 11.5 months (range 6–19). One failed to attend follow up. Most patients in whom the implant survived were afforded good pain relief by the procedure and had a good functional range of thumb movement. Radiologically 8 implants were subluxed by at least 50%. One implant was revised after dislocation and loosening of the prosthesis which was associated with trauma. She made excellent clinical progress after revision of the prosthesis. One of the thirteen cases dislocated and was revised to a trapeziumectomy after 11 months. Preliminary results suggest that this implant affords good pain relief and functional improvement in managing OA at the TMC joint. Longer term follow up will be required to correlate clinical and radiological outcomes

Background. Comminuted radial head fractures are challenging to treat with open reduction and internal fixation. Complicating matters further, radial head fractures are often associated with other elbow fractures and soft tissue injuries. Radial head arthroplasty is a favorable technique for the treatment of radial head fractures. The purpose of this study was to evaluate the functional outcomes of radial head arthroplasty using Modular Pyrocarbon radial head prosthesis in patients with unreconstructible radial head fractures. Methods. This single surgeon, single centre study retrospectively reviewed the functional and radiological outcomes of 21 consecutive patients requiring radial head arthroplasty for unreconstructible radial head fractures between July 2003 and July 2009. Patients were at least one year post-op and completed a Short-Form 36 (SF-36) questionnaire, the Disabilities of the Arm, Shoulder and Hand (DASH) questionnaire, and the Mayo Elbow Performance Index (MEPI). These patients were independently physically examined and their post-operative radiographs were independently reviewed. Results. 21 patients (9 males and 12 females) were reviewed at a minimum of 12 months follow-up. The mean DASH score was 10.8 (0-34.1), the mean SF-36 physical score was 76.9 (35-96), the mean SF-36 mental score was 83.8 (60-94), and their MEPI score was 86.4 (70-100). Patients maintained 90% of their grip strength in their injured arm when compared to their un-injured arm and had 17. o. of fixed flexion in the affected arm. Radiologically, 14 cases had some degree of post-traumatic osteoarthritis, 12 cases had evidence of heterotrophic ossification, 5 had some evidence of periprosthetic lucency and 3 of our cases were radiologically but not functionally ‘overstuffed’. Conclusion. Radial Head Arthroplasty with Pyrocarbon Radial Head Prosthesis is a safe and effective option when treating unreconstructable comminuted radial head fractures yielding good functional and radiological outcomes and remains the treatment option of choice at our institution

The aim of this study is the presentation of the midterm results of the radial head replacement with pyrocarbon head prosthesis (MoPyc). Thirty two patients (20 males and 12 females) with a mean age of 54 y.o. (32–68 y.o.) were subjected to replacement of the radial head with a pyrocarbon head prosthesis. Twenty of them had a comminuted radial head fracture(15 Mason IV type and 5 Mason III), two had a malunion and ten had a complex elbow injury (ligamentous rupture and comminuted radial head fracture with/without coronoid process fracture). In 22 patients the fracture was on the dominant side. The mean follow up time was 27 months (21 – 46 months). The post-operative results were:. The mean range of motion in flexion-extension was 130° (105° to 150°), while in pronation and supination was 74° (60°–80°). The mean grip strength was 96% of the contralateral side. There was no clinical laxity in the varus or valgus stress test. According to the Broberg-Morrey score the good and excellent result were 77%, while according to the Mayo Clinic Elbow Performance Score (MEPS) good and excellent results were up to 97% of the total. Pain was evaluated with a visual analogue scale. Finally there was also a radiographic evaluation of the patients (that yielded six cases of loosening or osteolysis without any clinical manifestation). Replacement of the radial head with the specific prosthesis leads to very satisfactory results when performed under specific indications

Purpose. Evaluation of our experience on the treatment of comminuted, radial head fractures, and of the outcomes of pyrocarbon prosthetic replacement in such cases. Materials and Methods. We evaluated 47 cases of prosthetic replacement, performed from May 2003 to July 2008. There were 18 males and 29 females with an average follow-up of 48 months (12 to 60). The Hotchkiss classification was used to characterize the fractures. The indicators for the procedure were type III fractures in 27 cases, type IV fractures in 10 cases, comminuted radial head fractures (associated with disruption in medial collateral ligament) in 3 cases, Monteggia variant in 5 cases, and Essex Lopresti in 2 cases. Functional outcomes were assessed using the Mayo Elbow Performance Index and the Visual Analog Scales (VAS) of pain, joint motion, and stability. Results. The mean VAS score for elbow pain was 1 (0.5–2.1). Patients showed an average arch of motion from 6 degrees to 140, with 75 degrees of pronation, and 67 of supination. By the Mayo Elbow Performance Index, 42 patients had good to excellent results, 3 fair, and 2 poor. The complications that we have encountered were: implant dislocations (2 cases), elbow stiffness (1), implant dissociation (1), stem rupture (1), and transient PIN palsy (2 cases with complete recovery of nervous function at 5 and 8 weeks). There was no persistent instability, infection, synosthosis, severe degenerative changes, or impingement. Conclusion. The pyrocarbon implants are a good treatment option in complicated, radial head fractures, but the outcome depends on the severity of the initial fracture and the associated lesions. We have also encountered a tendency towards overestimating the prosthesis size, causing restriction of motion, impingement, overstuffing, or dislocation. For these results we are now using the non-modular prosthesis in our center, but further studies are required

Aims. We performed a systematic review of the current literature regarding the outcomes of unconstrained metacarpophalangeal joint (MCPJ) arthroplasty. Materials and Methods. We initially identified 1305 studies, and 406 were found to be duplicates. After exclusion criteria were applied, seven studies were included. Outcomes extracted included pre- and post-operative pain visual analogue scores, range of movement (ROM), strength of pinch and grip, satisfaction and patient reported outcome measures (PROMs). Clinical and radiological complications were recorded. The results are presented in three groups based on the design of the arthroplasty and the aetiology (pyrocarbon-osteoarthritis (pyro-OA), pyrocarbon-inflammatory arthritis (pyro-IA), metal-on-polyethylene (MoP)). Results. Results show that pyrocarbon implants provide an 85% reduction in pain, 144% increase of pinch grip and 13° improvements in ROM for both OA and IA combined. Patients receiving MoP arthroplasties had a reduction in pinch strength. Satisfaction rates were 91% and 92% for pyrocarbon-OA and pyrocarbon-IA groups, respectively. There were nine failures in 87 joints (10.3%) over a mean follow-up of 5.5 years (1.0 to 14.3) for pyro-OA. There were 18 failures in 149 joints (12.1%) over a mean period of 6.6 years (1.0 to 16.0) for pyro-IA. Meta-analysis was not possible due to the heterogeneity of the studies and the limited presentation of data. Conclusion. We would recommend prospective data collection for small joint arthroplasties of the hand consisting of PROMs that would allow clinicians to come to stronger conclusions about the impact on function of replacing the MCPJs. A national joint registry may be the best way to achieve this. Cite this article: Bone Joint J 2017;99-B:100–6

Abstract: Although the unconstrained pyrocarbon prosthesis (Ascension®) has been presented as a new alternative in the treatment of idiopathic arthritis of the proximal interphalangeal joint of the hand a few years ago, there is still a lack of studies analyzing the results of this implant. In this study 10 patients (13 implants), that were tretated with this type of prosthesis between february 2002 and january 2005 were studied. All but one patient were satisfied with the postoperative situation and would agree to another operation. A significant pain reduction was observed. The average ROM was 58degrees. Five patients demonstrated a free extension, two patients had a swan neck defomity, which could be actively compensated for, and the remaining six patients had an extension deficit of 30–45degrees. The average flexion was 76° (+/−12°). X-ray examination was unremarkable in eight patients with a regular position of the endoprosthesis. However, in five patients significant radiolucent lines (> = 1mm) were observed. So far, a luxation of the prosthesis has not occurred and all implants are still in-situ. However, a dorsal tenoarthrolysis had to be performed in 3 patients. The results of this study show a high rate of patient satisfaction with a significant pain reduction. The radiological results have to be closely monitored in the future. Long-term results with a higher number of patients are necessary. A central registry for finger implants is recommended

Background The AscensionTM MCP-implant acc. to Beckenbaugh is an unconstrained endoprosthesis consisting of a graphite core with a pyrocarbon coating. Long term results published by the Mayo Clinic gave rise to the hope of good ingrowth properties and a long durability due to the optimum wear resistance of the material. Purpose of this study was the evaluation of the early results of this implant applied on the patients of a rheumatoid arthritis surgery department. Methods In a prospective manner we evaluated the data of 18 patients with 19 involved hands in which we implanted a total of 29 Ascension endoprostheses between July, 2000 and Oktober, 2002. The mean follow up time was 39.7 months. We assessed hand function (SODA-score), mobility, radiographic appearance and the subjective parameters pain, functionality, power, cosmetic appearance and global satisfaction. Results The SODA score increased from 82.8 preoperatively to 92.9 (maximum 108) at follow up. With 50.9 and 51.3 deg. respectively the range of motion remained almost unchanged. On a visual analogue scale from 0 – 10 the subjective results were: pain 2.1 (−5.2), functionality 6.5 (+3.0), power 5.3 (+2.3), cosmetic appearance 8.0 (+3.4), global satisfaction 8.1. Radiographically we observed suspicious radiolucent lines around 17 of 58 implanted components (29%), three of them progressive. Around the tips of three stems an osteolytic area with minimal progression was found. Three stems showed a slight migration. The following intraoperative complications were observed: Two bone fissures and three lacerations of a collateral ligament, which all healed uneventfully. Five endoprostheses were converted into a flexible hinge silicone implant for persistent pain and loosening between 12 and 48 months p.o. One more implant had to be revised due to a late haematogenous infection 4 years p.o. Conclusion With the AscensionTM MCP implant a good pain relief can be obtained in almost every case but only rarely an improvement in the range of motion can be seen. The subjective results were predominantly good. But the apparently inconstant bony ingrowth resulted in a rate of revisions for aseptic loosening as high as 17% at a mean follow up of 3 ½ years. A modification of the implant leading to a better bony fixation would be required before a wider clinical use of this implant can be recommended

Trapeziometacarpal arthritis is a common condition, causing symptoms in up to ten percent of women and one percent of men¹. LRTI is the most commonly used surgical technique for this condition however, long-term studies have shown persistent weakness of pinch strength² after surgery. The Ascension® PyroDisk is a pyrocarbon disk shaped implant designed to articulate against the trapezium and metacarpal, preserving the height of the articulation. The objective of this study was to determine whether treatment with a pyrocarbon implant resulted in comparable pain relief and range of motion, whilst providing superior gains in pinch strength when compared to LRTI. This is a prospective randomized control trial comparing pyrocarbon implant to LRTI. Surgeries were accomplished by a single surgeon in a standardized fashion. Patients were evaluated at six weeks, three, six and 12 months following surgery. Data on pain (VAS), function (Patient Rated Wrist Evaluation (PRWE)), mobility and strength (grip, key and lateral pinch) were obtained as well as radiographic assessment of the height of the arthroplasty space. A total of 80 patients had surgery between July 2008 and November 2016. Forty patients were allocated to the PyroDisk group and 40 to the LRTI group. Seventy-four patients (92,5%) completed the one year follow-up. Mean age was slightly older in the PyroDisk group (64 vs 60,8 y.o., p=0,03). Surgical and tourniquet times were longer in the PyroDisk group. There was no difference between the groups in strength, pain or functional outcome at one year. However, VAS was significantly higher in the PyroDisk group at three and six months (4,5 vs 2,4, p < 0,001, 2,6 vs 1,7, p=0,02) and PRWE was also significantly better at three months in the LRTI group (53,7 vs 71,2, p=0,02). The overall complication rate was three times higher in the PyroDisk group (10% vs 30%). Treatment of trapeziometacarpal arthritis with PyroDisk does not provide superior functional gains when compared to LRTI. On the contrary, it seems to result in more pain in the first few months following surgery. This difference in pain is not seen at 1 year after surgery. This may suggest that there is a period of adaptation to the Pyrodisk after its insertion. We also found a higher risk of complications with the use of the PyroDisk

Background. Simply stated, carbon reinforced carbon (C/C) may be considered as fibre reinforced pyrocarbon. Pyrocarbon is used e.g. in finger joints and artificial heart valves. Aim of the present study was to evaluate if C/C could broaden the field of orthopaedic applications compared to pyrocarbon. Technically, C/C is used e.g. for brakes of F-1 race cars. Methods. The mechanical strength of the C/C material was characterised by a biaxial flexural bending test according ISO 6474-1. Three C/C shoulder heads articulating against vitamin E stabilised, highly cross-linked UHMWPE (E-XLPE) underwent a shoulder simulator study up to 106 cycles. The Coefficient of Friction (CoF) of C/C disks (Ra: 0.045 μm) against cartilage was analysed by a reciprocal cartilage wear tester. The test was conducted in cell culture medium for 4 h and 12 h using bovine cartilage. All test data is compared to the corresponding test results with Al2O3 ceramic. Conclusions. The strength of C/C is 30 % lower than that of Al2O3 ceramic. Its wear rate measured in the shoulder simulator against E-XLPE is in tendency higher than that of ceramic heads. The CoF against cartilage is double compared to the same test with Al2O3. - C/C seems to have limited a potential as material for orthopaedic application. However, more investigations and optimisation of the C/C type and quality are necessary. Level of evidence. Laboratory test on material samples. Study financed by Mathys Ltd Bettlach

The June 2012 Wrist & Hand Roundup. 360. looks at; radial osteotomy and advanced Kienböck's disease; fixing the Bennett fracture; PEEK plates and four-corner arthrodesis,;carpal tunnel release and haemodialysis; degloved digits and the reverse radial forearm flap; occupational hand injuries; trapeziometacarpal osteoarthritis; fixing the fractured metacarpal neck and pyrocarbon implants for the destroyed PIPJ

Aims

Metal and ceramic humeral head bearing surfaces are available choices in anatomical shoulder arthroplasties. Wear studies have shown superior performance of ceramic heads, however comparison of clinical outcomes according to bearing surface in total shoulder arthroplasty (TSA) and hemiarthroplasty (HA) is limited. This study aimed to compare the rates of revision and reoperation following metal and ceramic humeral head TSA and HA using data from the National Joint Registry (NJR), which collects data from England, Wales, Northern Ireland, Isle of Man and the States of Guernsey.

This annotation reviews current concepts on the three most common surgical approaches used for proximal interphalangeal joint arthroplasty: dorsal, volar, and lateral. Advantages and disadvantages of each are highlighted, and the outcomes are discussed.

Cite this article: Bone Joint J 2022;104-B(12):1329–1333.