Locking of the MCP joint of the finger, except with stenosing tenosynovitis, is relatively rare. The middle finger is most frequently involved. We treated 7 patients who had locking of the MCP joint of the middle finger because of osteophyte of the metacarpal head. The locking of the MCP joint usually occurred in the older patient as a result of significant osteophyte around the metacarpal head. Unlocking of the MCP joint was done by closed manipulation under local anaesthesia. Locking of the MCP joint of the finger because of other causes than tenosynovitis has been reported infrequently. Locking of the MCP joint caused by osteophyte of the head of the metacarpal is characterised by painful loss of extension of the MCP joint without loss of flexion. We have treated 7 patients who had locking of the MCP joint occurring in the middle finger with an obvious osteophyte of the metacarpal head. Seven patients, 4 women and 3 men, were treated in our Department. None of the patients had a history of trauma to their hands, and in all of them it was the dominant hand which was affected and usually due to powerful full flexion movement of the fingers. The average age was 73.8 years (65 – 81). The duration of locking was from 3 hours to 14 days. All the patients were treated within 30–60 minutes after reporting to our Clinic. The presentation of the patients was extremely similar. In all cases active and passive extension was blocked and they had pain around the finger. Full flexion was possible. The MCP joint was tender around the palmar aspect with slight diffuse swelling around the dorsal aspect. Radiographs of the MCP showed degenerative changes in all the patients and oblique views demonstrated an osteophyte either on the ulnar or the radial side of the head. Local anaesthetic Lignocaine 1% 5ml was injected in the MCP and around the joint and after 5–10 minutes manipulation was performed, unlocking achieved and the patients straightaway extended and flexed the finger fully. No-one underwent surgical release. Follow-up from 3 to 8 months, average 6 months. No recurrence of the locking. Akio Minami reported 4 cases of MCP joint locking of the middle finger, treated surgically. Williams classified the locking of the MCP joint in 3 groups. Langenskiold reported 2 cases of intrinsic locking of the MCP due to catching of the collateral ligament on the lateral bony projection of the metacarpal head. It is very difficult to explain why the middle finger is most likely affected. Kessler noted that the MCP joint seldom participates in a generalised degenerative OA

Aims. Complete ruptures of the ulnar collateral ligament (UCL) of the thumb are a common injury, yet little is known about their current management in the UK. The objective of this study was to assess the way complete UCL ruptures are managed in the UK. Methods. We carried out a multicentre, survey-based cross-sectional study in 37 UK centres over a 16-month period from June 2022 to September 2023. The survey results were analyzed descriptively. Results. A total of 37 centres participated, of which nine were tertiary referral hand centres and 28 were district general hospitals. There was a total of 112 respondents (69 surgeons and 43 hand therapists). The strongest influence on the decision to offer surgery was the lack of a firm ‘endpoint’ to stressing the metacarpophalangeal joint (MCPJ) in either full extension or with the MCPJ in 30° of flexion. There was variability in whether additional imaging was used in managing acute UCL injuries, with 46% routinely using additional imaging while 54% did not. The use of a bone anchor was by far the most common surgical option for reconstructing an acute ligament avulsion (97%, n = 67) with a transosseous suture used by 3% (n = 2). The most common duration of immobilization for those managed conservatively was six weeks (58%, n = 65) and four weeks (30%, n = 34). Most surgeons (87%, n = 60) and hand therapists (95%, n = 41) would consider randomizing patients with complete UCL ruptures in a future clinical trial. Conclusion. The management of complete UCL ruptures in the UK is highly variable in certain areas, and there is a willingness for clinical trials on this subject. Cite this article: Bone Jt Open 2024;5(8):708–714

Intra-operative fluoroscopy in thumb metacarpophalangeal joint arthrodesis has been recommended as a means of achieving optimal alignment more consistently. This is not our current practice. A patient attending dissatisfied with an arthrodesis in excessive flexion performed outwith our unit highlighted the potential for problems, and we therefore elected to review our own outcomes. An evaluation of the alignment achieved in thumb metacarpophalangeal joint arthrodeses, to determine if current outcomes satisfactory or if fluoroscopic assistance should be considered. Radiological review of alignment of thumb metacarpophalangeal joint arthodeses carried out by two Consultant Surgeons with specialist interests in upper limb surgery in a District General hospital. Cases were predominantly identified retrospectively from sequential review of operating lists. The radiological images were, or had been taken, as part of routine follow-up and were not standardised. The alignment was also assessed independently by a junior doctor with no involvement in the patient's surgical treatment and no knowledge of the intended alignment. Recommended positions for arthrodesis have covered a range from 0 to 30 degrees, so for the purposes of analysis that range was considered acceptable. 14 cases had an average fusion position of 18 degrees flexion (range 6 to 30 degrees). 6 underwent concurrent ipsilaterel trapeziectomy. The series achieved satisfactory alignment radiologically without the routine use of intra-operative fluoroscopy

Introduction. An understanding of anatomic variability can help guide the surgeon on intervention strategies. Well-functioning thumb metacarpophalangeal joints (MCPJ) are essential for carrying out typical daily activities. However, current options for arthroplasty are limited. This is further hindered by the lack of a precise understanding of the geometric variation present in the population. In this paper, we offer new insight into the major modes of geometric variation in the thumb MCP using Statistical Shape Modelling. Methods. Ten participants free from hand or wrist disease or injury were recruited for CT imaging (Ethics Ref:14/LO/1059). 1. Participants were sex matched with mean age 31yrs (range 27–37yrs). Metacarpal (MC1) and proximal phalanx (PP1) bone surfaces were identified in the CT volumes using a greyscale threshold, and meshed. The ten MC1 and ten PP1 segmented bones were aligned by estimating their principal axes using Principal Component Analysis (PCA), and registration was performed to enable statistical comparison of the position of each mesh vertex. PCA was then used again, to reduce the dimensionality of the data by identifying the main ‘modes’ of independent size and shape variation (principal components, PCs) present in the population. Once the PCs were identified, the variation described by each PC was explored by inspecting the shape change at two standard deviations either side of the mean bone shape. Results. For the ten MC1s, over 80% of the variation was described by the first two PCs (Table 1). Figure 1 shows the effect of the variation in PC1. The majority of geometric variation of the ten PP1s was also described by the first two PCs, with PC1 describing 78.9%. Figure 2 shows the effect of this component on the mean bone geometry. Both the distal articulating surface (head) of the MC1 and the proximal articulating surface (base) of the PP1 vary in overall size. However, the MC1 head also varies in shape (curvature), whereas the PP1 base does not appear to undergo noticeable variation in shape. In this study population, smaller MC1 was observed to correlate with a flatter head, whereas the PP1 head shape did not vary with size. Discussion. The flatter MC1 head (smaller height-radius ratio) may have implications for MCPJ instability, and possibly for osteoarthritic degeneration. A recent study predicted similar trends for the first CMC joint. 2. Previous investigation also observed correlation between MC1 head curvature and MCPJ RoM. 3. , which may explain clinical observations of differing thumb movement strategies. This study used a convenience sample and cannot describe a full population's variability, though the high variance captured by only two PCs suggests adequate external validity amongst similar populations. Further confidence would be gained from studying the joint (i.e. single PCA containing both bones), and wider populations. Significance. These data: provide more precise description of anatomic variation; may offer insights into thumb movement strategies and MCPJ osteoarthritic degeneration. 4. ; and support implant design for individuals whose anatomy can bear an anatomic reconstruction. For any figures or tables, please contact the authors directly

Introduction: The thumb metacarpophalangeal (MCP) joint dislocations in children are relatively uncommon and scarcely described in the English literature. The aim of this study was to report the clinical course and outcome of traumatic dislocations of the thumb metacarpophalangeal joints in children. Materials and methods: We retrospectively reviewed a cohort of 37 traumatic dislocations of the thumb metacarpophalangeal joints in 37 children between 1990 and 2005. All patients were treated by five orthopaedic surgeons at a tertiary referral children’s hospital. The outcome measures included patient demographics, method of reduction and short-term outcome. The mean follow-up was 6 weeks. Results: The mean age at injury was 7.3 years. These occurred predominantly in boys (78.3%) and were dorsal dislocations in 97.2%. Thirty-three presented acutely on the day of injury, while 3 within 1–2 weeks. Four patients needed open reduction with or without temporary stabilisation. Thirty-three had a closed reduction (under general anaesthesia-12, under ring block-5, under sedation-9 and without anaesthesia-7). All patients undergoing closed or open reduction under anaesthesia had 1–4 unsuccessful relocation attempts. Two of four open reductions revealed soft tissue interposition of volar plate and flexor pollicis longus. Post-reduction, the thumb was immobilised in a thumb spica or plaster for 2 to 3 weeks period. All gained good result. There were no infections, recurrent dislocation or gross stiffness. Conclusion: Thumb metacarpophalangeal (MCP) joint dislocations in children are mostly dorsal and managed non-operatively in majority with satisfactory outcome. Irreducible dislocations may need open reduction due to volar plate and flexor pollicis longus tendon interposition

Since November 2003 there have been 62 Metacarpophalangeal Joint (MCPJ) replacements carried out on 16 patients at Macclesfield District general hospital. 11 of the patients were female and 5 were male. The mean patient age at procedure was 64.9 years, with an age range of 28 to 80. Of the 62 MCPJ replacements carried out, 58 (93.5%) were as a result of rheumatoid arthritis, with only 4 (6.5%) as a result of osteo-arthritis. The primary objective of this study is to assess their outcomes to date. Data was collected retrospectively by means of case note review. Outcomes measured were patient rating of pain and function at post operative review and post operative complications. All operations were carried out by a single surgeon, using his standard operative technique, and all replacements used the Neuflex Finger Joint Implant System. All 16 patients attended for post operative review. At the time of discharge 13 patients rated their outcome as excellent to good, 1 patient was deceased and 2 patients are currently under follow up with no reported complications. Mean time to discharge was 19 months (2–68). Of the total 62 joints replaced, 10 revisions were carried out. Of these, 3 were as a result of dislocation, 6 were for subluxation and 1 as a result of failure of the prosthesis. There were 3 other post operative complications; 1 was for superficial wound infection, 1 resulting from a prominent prosthesis and 1 hypertrophic scar. Results showed that 81.3% of patients rated their range of movement as good to excellent and 87.5% reported an improvement in pain. Overall, 81% of patients rated their outcome at discharge as good to excellent. From the data available we conclude that the Neuflex system is an effective treatment method with a low complication rate

The aim was to compare the medium term results of metacarpophalangeal joint (MCPJ) arthroplasty using three different types of silicone hinged implants. All rheumatoid arthritis patients undergoing four finger MCPJ arthroplasty at Burwood Hospital have had standardised pre and post operative assessments for up to four years consisting of: measurement of MCPJ active arc of motion (AOM); finger ulnar drift (UD) and the Baltimore upper extremity function test (UEFT). All surgery was undertaken or directly supervised by one surgeon using a standardised technique followed by a dynamic and static splintage programme supervised by the same hand therapists. Implants – Swanson; 25 hands, 100 joints, 1989 to 1995 – Avanta; 27 hands, 108 joints, 1995 to 2000 – Neuflex; 11 hands, 44 joints, 1999 to 2003. Swanson – at two years the AOM changed from 46 – 80° to 15 – 51°; UD reduced from 33 to 4°and 66% had improved from partial and poor to functional UE categories. Avanta – the AOM changed from 51 – 79 to 15– 60; UD from 31 to 7° and 67% had improved to functional. Neuflex – the AOM changed from 42 – 68 to 17 – 63°; UD from 32 to 11 and 45% had improved to functional classification. From two to four years the UEFT for the Swanson and Avanta had significantly deteriorated. The medium term outcomes for the three implants were very similar. Neuflex use was discontinued in 2003 because of early recurrence of ulnar drift. The significant deterioration of hand function from two to four years is likely to be the effect of progressive rheumatoid disease as the AOM and UD remained unchanged

Objective

We explanted NeuFlex metacarpophalangeal (MP) joint prostheses to identify common features, such as position of fracture, and thus better understand the reasons for implant failure.

Purpose: Trauma to the radial collateral ligaments requires the same attention as trauma to the ulnar ligaments. Damage is uncommon due to the particular anatomic position, but nevertheless a distinct clinical entity.

Material and methods: We report a retrospective analysis of 14 patients, eight who underwent emergency surgery and six with trauma sequelae. Mean follow-up was 22 months and mean age 37 years. Among the recent lesions, the pain score (scale from 1 to 5) was 4.5) and the instability score (scale from 1 to 3) was 3. Palmar subdislocation was 4.8 mm and laxity was 16.7°. Among the old lesions (> 1 month) the corresponding data were pain 3.3, instability 2.5, palmar sub-dislocation 4.2 mm, laxity 19.1°. Two patients had signs of osteoarthritis. At surgery, the phalanx and metacarpus were equally injured. Associated lesions (capsule, short abductor) were present in 78% of the patient. The radial collateral ligaments and the soft tissue were reinserted or retightened in all cases. One patients required arthrodesis due to cartilage damage.

Results: Among the recent injuries, 71% reached a good subjective result: amplitude loss (flexion/extension) was 17°, force was 75% and laxity was 5°. Two patients had palmar subdisloction. Among the older lesions, a good subjective result was achieved in 66%: loss of amplitude case 32°, force was 69% and laxity was 8°. Palmar subdislocation was 2 mm on the average. We had two cases of persistent dysaesthesia.

Discussion: Radial injury appears to be falsely benign because the Stener lesion is not found on this side of the metacarpophalange. The importance of the injury in these traumas is related to the vulnerability of the dorsal region of the medial collateral ligament and is probably the cause of poor outcome after surgery for older lesions with palmar dislocation which is difficult to correct. We advocate emergency surgery for a wide range of indications. We always operate major radial laxity (> 35°) or laxity associated with palmar subdislocation. For other cases, we use the anterior forced drawer view to disclose potential associated dorsal injury.

Aims. The objective of this systematic review was to describe trapeziectomy outcomes and complications in the context of osteoarthritis of the base of the thumb after a five-year minimum follow-up. Methods. Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines were used to guide study design, and 267 full-text articles were assessed for eligibility. After exclusion criteria application, 22 studies were included, involving 728 patients and 823 trapeziectomies. Outcomes included pre- and postoperative clinical and radiological characteristics. Complications and revisions were recorded. Results. All the studies reported good results regarding pain and range of motion at the last follow-up of 8.3 years (5 to 22); the mean satisfaction rate was 91% (84% to 100%). It was difficult to assess the impact on metacarpophalangeal joint motion in extension with contrary results. The key pinch returned to its preoperative values, whereas tip pinch showed a modest improvement (+14%), with a mild improvement found in grip strength (+25%) at the last follow-up. The mean progressive trapezial collapse was 48% (0% to 85%) and was not correlated with pain, grip strength, or satisfaction. The most represented complications were linked to tendons or nerves affected during additional procedures to stabilize the joint (11.6%; n = 56). Mechanical complications included symptomatic scapho-M1 impingement (3.1%; n = 15/580), leading to nine surgical revisions out of 581 trapeziectomies. Meta-analysis was not possible due to study heterogeneity and limited data. Conclusion. After a minimum five-year follow-up, trapeziectomy achieved high patient satisfaction and pain relief. However, strength seemed to be deteriorating with detrimental consequences, but this did not correlate with trapezial collapse. The issues related to underestimating mechanical complications and varying degrees of success should be highlighted in the information given to patients. Evidence-based analyses should help the surgeon in their decision-making. Cite this article: Bone Jt Open 2021;2(3):141–149

Introduction: The metacarpophalangeal joint of the thumb is prone to frequent injury in the capsule and collateral ligaments, especially the ulnar collateral ligament. Delayed diagnosis, inappropriate treatment or progressive laxity of the ligament complex can lead to chronic instability of the MCP joint of the thumb. Various surgical repair procedures have been described. We present the surgical procedure consisting of a bone-retinaculum-bone autograft taken from the second tunnel of the flexor retinaculum of the carpus. Purpose: Our purpose is to present the experience of seven cases in which chronic instability of the thumb was treated using a bone-retinaculum-bone autograft. Materials and methods:. Type of study: Descriptive. Period: 2003–2004. Number of cases: 7 (4 women and 3 men) aged 23 to 65. Injury-to-surgery time more than one year. Results:. - We achieved stability of the MCP joint in all cases. - The metacarpophalangeal and interphalangeal joint balance was not diminished. - The grasp force was sustained at over 80% of that of the healthy side. - Two elderly women were not employed; the other five returned to their previous jobs. Conclusions: Given the results obtained, we think this is an excellent method for deferred reconstruction of thumb instability and, although it involves considerable technical difficulty, we feel it is an option to bear in mind for this type of injury

Introduction. An educated public are becoming increasingly aware of percutaneous needle fasciotomy (PNF) for the treatment of Dupuytren's contracture. We believe that it has an important place in the management of this condition and have set up a dedicated one-stop clinic to perform this procedure. Methods. A prospective study of 61 patients with Dupuytren's, who have undergone PNF have been recruited so far. The study population includes 50 men and 11 women. The average age is 65. The senior author has operated on 81 fingers including 69 MCP joints, 62 PIP joints and 6 DIP joints. We recorded contractures prior to PNF and immediately following the procedure, as well as any complications. At follow up we recorded the Patient global impression of change (PGIC), DASH scores, degree of straightness of the operated finger and whether they would have the procedure again or recommend it. Results. For MCP joints the average pre treatment contracture was 43. o. and immediately post operatively it was 3. o. For PIP joints the average pre treatment contracture was 48. o. and immediately post operatively it was 17. o. For DIP joints the average pre treatment contracture was 41. o. and immediately post operatively it was 20. o. 8 patients had small skin tears and 2 found it too uncomfortable to continue. No nerve or tendon injuries. Mean follow up was 9 months (6–24). At follow up the average PGIC was 6 (very good) and the average DASH score was 30.9 (excellent). Subjectively the vast majority of fingers remained straight. All but 4 patients would have the procedure again and would recommend it to others. Discussion. This specialist clinic offers a very effective, safe procedure and our patients are highly satisfied withthe results. It is also cost effective for our Department

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

Apoptosis of articular chondrocytes may play an important role in the pathogenesis of osteoarthritis (OA). The aim of this study was to investigate the incidence of chondrocyte apoptosis in equine articular cartilage (AC) specimens and examine the relationship between the process of cell death and the degree of cartilage degradation. The study comprised 2 populations of equine cartilage taken from the left forelimb. Population 1 (n=10) consisted of full depth cartilage from weight-bearing regions of equine metacarpophalangeal (MCP), proximal interphalangeal (PIP) and distal interphalangeal (DIP) joints. Population 2 (n=9) comprised cartilage from 6 different regions of the MCP joint: dorsomedial, dorsolateral, centromedial, centrolateral, palmarome-dial and palmarolateral areas. Cartilage from each horse for each of the joints and joint regions was not always available. Seven micrometre cryostat sections were obtained. Haematoxylin and Eosin with Safranin-O stained sections were used to score structural differences between samples for features of cartilage pathology using a ‘modified’ Mankin scoring system. Two methods were used to quantify apoptotic chondrocytes: a direct method in which chondrocytes were assessed for morphological features of apoptosis using a light microscope and an immunohistochemical staining technique to detect the expression of active caspase-3 using a commercially available monoclonal antibody. Apoptosis assessed by the direct method did not show any association with increasing severity of OA (r=0.11, p=0.7205). Overall there was a positive correlation between caspase-3 expression and cartilage damage (r= 0.44, p=0.0043). Caspase-3 expression was found to increase linearly with increasing severity of OA in the superficial, middle and deep zones of AC (r=0.36, p=0.0198; r=0.49, p=0.0011 and r=0.37, p=0.0237 respectively). Moreover, caspase-3 expression was higher in the superficial and middle zones than in the deep zone (p< 0.001). In the superficial, middle and deep zones the expression of caspase-3 was higher in the MCP joint than the PIP joint (p< 0.05, p< 0.01 and p< 0.05 respectively). The significant positive correlation between disease severity and chondrocyte apoptosis, suggests that this process plays an important role in the pathogenesis of OA. The differences in the extent of apoptosis observed in different joints could be explained by the biomechanical environment of the joints

Rheumatoid arthritis is a whole body, lifetime incurable disease. The problems engendered by the disease process itself are highly individual, given that each set of problems that a patient has, the assessment and planning of surgery is a crucial aspect of the appropriate management of patients with polyarthritis. The presence of deformity does not necessarily indicate a problem of function, but one has to accept that certain deformities cause more problems than others and I draw your attention to swan neck deformity being relatively function-impairing and Boutonnière deformities less so. There is always a balance between the risk of surgery and the benefits to be obtained. The assessment is functional, anatomical, radiological, psychological, medical, financial and, finally, surgical. The functional assessment is intended to identify the problems a patient has in the activities of daily living, the anatomical assessment identifies the structures damaged which need to be prepared or replaced, the x-rays define the bone loss and, therefore, determine the limits of bony surgery, the psychological aspect identifies the patient’s capacity and willingness to be involved in often quite complex therapy programmes over a significant period of time. The medical problems of vasculitis and active disease are less frequent now but are contra-indications to surgery in the acute phases. The financial aspects are often under-rated. The costs of maintaining someone with significant disabilities is really quite great and, therefore, although surgery may only give some small improvement in function, it often has quite a significant impact on the degree of care and help an individual needs. Finally, the surgical assessment is to identify which structures and in which order. In terms of planning, the surgical priorities, described by Nalebuff, are:. 1 Nerves 2 Flexor tendons 3 Wrist 4 Thumb 5 MCP joints 6 Extensors 7 PIP joints 8 Distal Interphalangeal joints. Prolonged nerve compressions do not recover well; ruptures of flexor tendons are very difficult to treat; if the wrist is painful and unstable it inhibits any function that the hand might have; the thumb is 50% of hand function; metacarpophalangeal joints need to be stable and to flex approximately to 60° in order to be functional; extensor tendons need to glide and to be able to lift fingers away from the palm; the interphalangeal joints contribute greatly to the closing of grasp. The role of the therapist is pre-operatively to assess the patient appropriately for surgery, assessing all the aspects defined above and to ensure that the patient is compliant with the treatment post-operatively. The aphorism that 20% of the effort comes from the surgeon, 50% from the therapist and 20% from the patient is probably a fairly accurate representation of the importance of therapy post-operatively. Therapy must be planned, purposeful and progressive

Aim. We aimed to assess the efficacy of conservative management of proximal phalanx fractures in a plaster slab. Methods. 23 consecutive patients with proximal phalanx fractures were included in this prospective study. The fractures were reduced and the position was held with a dorsal slab for three weeks. They were followed up an average of 7 weeks (range 2 to 45) after the injury. Radiographic confirmation of adequate reduction was carried out each week until union. After removal of the plaster, range of motion of the finger and radiological evidence of union, non-union or malunion was documented. Results. In united fractures, an average angulation of 4° (apex volar) was measured (range 0 to 45°). In one case (45°) this was not acceptable. All other cases measured less than 15° of angulation. On the AP radiograph the angulation was on average 2° (range 0 to 8°). On average 1.3 mm of shortening (range 0 to 5mm) were measured. In one case delayed union with rotational deformity of 20° was evident. After removal of the slab mild stiffness was noted in one case at the metacarpophalangeal joint and in two cases at the proximal interphalangeal joint. Conclusion. Most proximal phalanx fractures can be managed conservatively with acceptable results. NO DISCLOSURES

In some centres, serial bedside aspirations, in association with intravenous antibiotics, are still an accepted treatment for septic arthritis (Mathews, Postgraduate Medical Journal, 2008). However, there is a risk that bacterial products remain in the joint, even when the bacteria have been destroyed. We have conducted a study to ascertain whether bacterial products alone have an effect on in situ chondrocyte viability. A hip aspirate (25μl), containing Staphylococcus aureus, from a patient with septic arthritis was added to 5ml culture medium and incubated (37°C) for 48hrs. The solution was then centrifuged (3400g for 10mins) and the supernatant removed. Cartilage explants were harvested from a bovine metacarpophalangeal joint, placed into the bacterial supernatant and incubated at 37°C. Explants were removed at hourly intervals over a 6-hour period and stained with the fluorescent probes chloromethylfluorescein di-acetate (10μM) and propidium iodide (10μM) to label living chondrocytes green and dead cells red respectively. Following imaging of cartilage by confocal microscopy, the percentage cell death at each time point was obtained using Volocity 4 software. Chondrocyte death increased markedly with time: 0.04% at 2hrs, 28% at 4hrs and 39% at 6hrs. This study shows that bacterial products rapidly penetrate the cartilage matrix and have a damaging effect on in situ chondrocyte viability. Further work will clarify the contributions made by the various toxic components in the culture supernatant, but these data support the need to remove the bacteria and their products aggressively as part of the treatment of septic arthritis

Staphylococcus aureus is a highly virulent pathogen and implicated in approximately 50% of cases of septic arthritis. Studies investigating other S. aureus-related infections suggest that alpha-(Hla), beta-(Hlb) and gamma-(Hlg) toxins are key virulence factors, with the ‘pore-forming’ alpha-toxin considered the most potent. Here, we have assessed the influence of alpha-toxin alone on in situ chondrocyte viability. Osteochondral explants were harvested from the metacarpophalangeal joints of 3-year-old cows and cultured in Dulbecco's Modified Eagle's Medium. The flasks were then inoculated with isogenic ‘knockout’ strains of S. aureus: DU5946 (Hla+Hlb-Hlg-: alpha-toxin only strain) or DU1090 (Hla-Hlb+Hlg+: beta- and gamma-toxin only strain). Explants were incubated (37°C) and stained after 18, 24 and 40hrs with chloromethylfluorescein-di-acetate and propidium iodide, labelling living chondrocytes green and dead cells red, respectively. Axial sections were imaged by confocal microscopy and the percentage cell death determined. Alpha-toxin-producing S. aureus caused 24.8+/−3.7% chondrocyte death at 18hrs and 44.6+/−7.2% death at 24hrs. At 40hrs, there was significantly more chondrocyte death (87.4+/−3.6%;p<0.001) compared to the alpha-toxin knockout strain, which was negligible (4.1+/−1.7%; means+/−SEM; N=4 independent experiments). In this in vitro bovine cartilage explant model, whereby the effects of defined toxins were determined in isolation of a complex host immune response, in situ chondrocyte viability was dramatically and exclusively reduced by alpha-toxin. This work forms the basis for developing a rational treatment to reduce the extent of cartilage destruction during an episode of septic arthritis. IDMS was supported by Orthopaedic Research UK and The Royal College of Surgeons of Edinburgh

We have demonstrated that toxins produced by Staphylococcus aureus, a common infective agent in septic arthritis (SA), cause rapid in situ chondrocyte death. Here, we have compared the sensitivity of chondrocytes within the superficial and deep zones (SZ, DZ) of cartilage to the same toxins. Culture medium containing the toxins produced by S. aureus strain 8325-4, which include alpha-, beta-, and gamma-toxin, was prepared. Cartilage explants free of subchondral bone were taken from the metacarpophalangeal joints of 3-year-old cows, and incubated (37°C) with the toxins. Explants were stained after 6hrs with chloromethylfluorescein-di-acetate and propidium iodide, labelling living chondrocytes green and dead cells red, respectively. Full-thickness coronal sections were imaged by confocal microscopy and the percentage cell death within the SZ (100μm from articular surface) and DZ (100μm from subchondral bone interface) determined. Both zones were incubated with the same toxin culture medium for the same time period. At 0hrs, chondrocytes within all zones were >98% viable. However, after incubation with toxin-containing culture medium for 6hrs, 71.9+/−11.2% of the SZ cells were dead compared to only 47.4+/−6.7% in the DZ (p=0.03;data are means+/−SEM;N=4). These results suggest that SZ chondrocytes are considerably more sensitive to S. aureus toxins than those within deeper zones. As SZ chondrocytes are close to the synovial fluid harbouring bacterial toxins, these data emphasise the need to remove bacteria and their products aggressively as part of the treatment of SA. IDMS was supported by Orthopaedic Research UK and The Royal College of Surgeons of Edinburgh

The internal fixation of osteochondral fragments in fractures normally utilizes intra-articular screws inserted through a pilot hole drilled into cartilage/bone. This trauma causes cartilage injury leading to chondrocyte death. We have quantified the cell death following cartilage drilling and identified irrigation conditions that can protect chondrocytes. Articular cartilage of bovine metacarpophalangeal joints of 3yr-old cows was irrigated in the presence/absence of saline of various compositions. Holes were then made using a standard 1.5mm drill (Ortho Solutions Ltd.) at 18,000 rpm through the articular cartilage into bone. Osteochondral explants were then harvested and cultured in Dulbecco's Modified Eagle's Medium containing chloromethylfluorescein-di-acetate and propidium iodide (10uM each), to label living chondrocytes green and dead cells red, respectively. Axial images were taken by confocal microscopy and the width of the zone of cell death (ZCD) around the hole determined. With no irrigation, new drills caused a ZCD of 171±25um, which was increased when drills used 50+ times were tested (279±31um;p=0.03). With saline irrigation, the ZCD was reduced for old drills (150±6um;p=0.016) but not for new drills (124±8um) suggesting the heating effect of the old drills caused additional chondrocyte death. However for new drills, the ZCD was further reduced significantly to 82±7um when the osmolarity of the saline irrigation solution was raised to 480mOsm using sucrose. Data are mean±s.e.m., from at least 5 separate experiments each with a minimum of 3 replicates. The results demonstrate a chondroprotective effect of raising the osmolarity of saline used during drilling of cartilage which could be clinically beneficial