INTRODUCTION

Combining novel diverse population-based software with a clinically-demonstrated implant design is redefining total hip arthroplasty. This contemporary stem design utilized a large patient database of high-resolution CT bone scans in order to determine the appropriate femoral head centers and neck lengths to assist in the recreation of natural head offset, designed to restore biomechanics. There are limited studies evaluating how radiographic software utilizing reference template bone can reconstruct patient composition in a model. The purpose of this study was to examine whether the application of a modern analytics system utilizing 3D modeling technology in the development of a primary stem was successful in restoring patient biomechanics, specifically with regards to femoral offset (FO) and leg length discrepancy (LLD).

Aims

Anatomical atlases document classical safe corridors for the placement of transosseous fine wires through the calcaneum during circular frame external fixation. During this process, the posterior tibial neurovascular bundle (PTNVB) is placed at risk, though this has not been previously quantified. We describe a cadaveric study to investigate a safe technique for posterolateral to anteromedial fine wire insertion through the body of the calcaneum.

“Simulation”, “deliberate practice”, “rehearsal” have been used to describe safe acquisition and practice of skills before patient contact. Simulation resources are being introduced as a General Medical Council mandate. Individual simulators have shown multi-level evidence but there is no guidance to form a simulation curriculum. We devised a pilot arthroscopy course based on a 4-stage model. Stage 1: session covering anatomy, equipment, and skills required; Stage 2: practice on low fidelity simulators (Arthroscopic Skills Acquisition Tools (ASATs), ArthroBox, Synthetic Knee); Stage 3: practice on high fidelity simulators (Cadaveric Knee, Virtual Reality); Stage 4: assessment on performance intra-operatively. This study sought feedback on Stages 1–3 with the aim that the feedback will help identify how trainees wish to use simulators.

Five arthroscopic simulators were used in this one-day pilot course. Prior to commencing, participants were asked which simulator they felt would help them the most. Feedback on each stage, and individual simulator (Likert scale), and how trainees would like to be trained was prospectively collected.

Seven orthopaedic juniors took part. All felt the high-fidelity simulators will be the most useful. All stages were ranked with equal importance, whilst cadaveric, plastic, VR, Arthrobox and lastly ASATs ranked in order of realism respectively. For cadaveric arthroscopy trainees wished the trainers to be there all the time (6/7), whilst for VR all trainees wanted their trainers part of the time.

We have shown that junior trainees value a structured method of skills acquisition and have identified that high fidelity simulation requires trainers to be present to provide relevant feedback. Such feedback mechanisms need to be incorporated in any curriculum so that simulation tools are not seen as a standalone training method.

Compartment syndrome (CS) is a unique form of skeletal muscle ischaemia. N-acetyl cysteine (NAC) is an anti-oxidant in clinical use, with beneficial microcirculatory effects.

Sprague-Dawley rats (n=6/group) were randomised into Control, CS and CS pre-treated with NAC (0.5g/kg i.p. 1 hr prior to induction) groups. In a post-treatment group NAC was administered upon muscle decompression. Cremasteric muscle was placed in a pressure chamber in which pressure was maintained at diastolic minus 10 mm Hg for 3 hours inducing CS, muscle was then returned to the abdominal cavity. At 24 hours and 7 days post-CS contractile function was assessed by electrical stimulation. Myeloperoxidase (MPO) activity was assessed at 24-hours.

CS injury reduced twitch (50.4±7.7 vs 108.5±11.5, p<0.001; 28.1±5.5 vs. 154.7±14.1, p<0.01) and tetanic contraction (225.7±21.6 vs 455.3±23.3, p<0.001; 59.7±12.1 vs 362.9±37.2, p<0.01) compared with control at 24 hrs and 7 days respectively. NAC pre-treatment reduced CS injury at 24 hours, preserving twitch (134.3±10.4, p<0.01 vs CS) and tetanic (408.3±34.3, p<0.01 vs CS) contraction. NAC administration reduced neutrophil infiltration (MPO) at 24 hours (24.6±5.4 vs 24.6±5.4, p<0.01). NAC protection was maintained at 7 days, preserving twitch (118.2±22.9 vs 28.1±5.5, p<0.01) and tetanic contraction (256.3±37 vs 59.7±12.1, p<0.01). Administration of NAC at decompression also preserved muscle twitch (402.4±52; p<0.01 versus CS) and tetanic (402.4±52; p<0.01 versus CS) contraction, reducing neutrophil infiltration (24.6±5.4 units/g; p<0.01).

These data demonstrate NAC provided effective protection to skeletal muscle from CS induced injury when given as a pre- or post-decompression treatment.

Objective

To compare the ability of a new composite bio-absorbable screw and two conventional metal screws to maintain fixation of scaphoid waist-fractures under dynamic loading conditions.

Assesment at teaching courses has been restricted to subjective assessment by questionnaire of the quality of teaching sessions and the teachers. This does not give any information on the extent of learning by the participants. Formal skills assessment during a practical course can be complex, time consuming and may distract from the teaching process. The purpose of the study was to quantify learning at a skills course on open shoulder surgery using a knowledge based questionnaire before and after completion of the course.

Method: 22 participants at a two day shoulder surgical workshop completed a knowledge questionnaire before (entry assessment) and immediately after completion (exit assessment) of the course. Four participants were excluded because of incomplete forms. The questionnaire consisted of 10 multiple choice questions which represented the content of the programme. The questionaires were scored and the change in score calculated for each participant and expressed as a percentage of the initial score. An improvement in the score defined a positive learning experience.

Results: There was a positive learning experience for all participating surgeons. The average improvement was 17% {range 4–43%}. The pre course scores ranged from 43 to 92% {average 68.8%}, while the post course scores ranged from 67 to 100% {average 85.5%}. The improvement was dependent on the initial score, trainees with low initial scores registering the maximum percentage recorded increase in knowledge ie 23% (range 5–43%). We did not identify a relationship between grade of surgeon and learning as measured with this assessment.

Conclusions: Simple learning assessments can demonstrate and quantify learning experience at skills courses. The process is not time consuming and can be easily integrated into the structure of a course.

Purpose: To find if there is any difference in gapping of tendon repair on cylcic loading and energy to failure of tendon repair when the circumferential suture knot is placed on the same side of the core suture knot or to the opposite side of the core suture knot.

Methods: Ten pig flexor tendons were repaired using 3 0 braided Polyester (Ethibond) as core suture (modified Kessler) and 6 0 Nylon as circumferential stitch (Hal-stead). Five tendons were repaired with the circumferential suture knot placed on the same side as the core suture (Group I) and the other five placed on the opposite side (Group II). Allocation to either of the groups was random. Using a testing machine the tendons were cyclically loaded and the energy to failure was calculated. Gapping during cylical loading was recorded using digital images.

Results: Mean gapping in Group I was 0.01 mm and in Group II was 0.03mm. This was not statistically signifi-cant (2x3 ANOVA, p > 0.3). The mean load to failure in group I was 58.7 N (55 to 65) and in group II was 59.5 N (54 to 67). This was also not statistically significant (p > 0.3 one way ANOVA).

Conclusion: There is no difference in gapping and energy to failure of tendon repair when the circumferential suture knot is placed on the same side of the core suture knot or to the opposite side of the core suture knot.

Objective: To compare the ability of a new composite bio-absorbable screw and two conventional metal screws to maintain fixation of scaphoid waist-fractures under dynamic loading conditions.

Methods: Fifteen porcine radial carpi, whose morphology is comparable to that of human scaphoids, were osteotomized at the waist. Specimens were randomized in three groups: those in group I were fixed with a headed metal screw, in group II with a headless tapered metal screw, and in group III with a bio-absorbable composite screw. Each specimen was oriented at 45° and cyclically loaded using four blocks of 1000 cycles, with peak loads of 40, 60, 80 and 100 N, respectively. In case of gross failure the number of cycles to failure was determined. Otherwise, permanent displacement at the fracture site was measured after each loading block from a standardized high-magnification photograph using image analysis software (Roman v1.70, Institute of Orthopaedics, Oswestry). Statistical analysis was by ANOVA and tolerance limits.

Results: Nogross failure occurred. Average displacements after 4000 cycles up to 100N were 0.05mm±0.03SD (headed metal), 0.15mm±0.16SD (headless metal) and 0.29mm±0.11SD (composite) and differed significantly (p< 0.02). Using tolerance limits, the data allowed us to predict that with 95% certainty, displacement in 95% of any sample fixed with a headed metal screw will be below 0.17mm, headless metal screw below 0.84mm, and composite screw below 0.76mm.

Conclusion: Comparing two types of conventional metal screws and a new composite bio-absorbable screw to maintain scaphoid fixation under cyclic loading conditions, we found small average fracture displacements for all three screws. Moreover, even following severe cyclic loading conditions, clinically meaningful displacements of more than 1 mm are highly unlikely for any of the three screws. We therefore conclude that a new bio-absorbable composite screw can serve as an alternative to conventional screws when fixing scaphoid fractures.

Objective: To compare the ability of a new composite bio-absorbable screw and two conventional metal screws to maintain fixation of scaphoid waist-fractures under dynamic loading conditions. Methods: Fifteen porcine radial carpi, whose morphology is comparable to that of human scaphoids, were osteotomized at the waist. Specimens were randomized in three groups: those in group I were fixed with a headed metal screw, in group II with a headless tapered metal screw, and in group III with a bio-absorbable composite screw. Each specimen was oriented at forty-five degrees and cyclically loaded using four blocks of 1000 cycles, with peak loads of 40, 60, 80 and 100 N, respectively. In case of gross failure the number of cycles to failure was determined. Otherwise, permanent displacement at the fracture site was measured after each loading block from a standardized high-magnification photograph using image analysis software (Roman v1.70, Institute of Orthopaedics, Oswestry). Statistical analysis was by ANOVA and tolerance limits.

Results: Nogrossfailureoccurred. Averagedisplacements after 4000 cycles up to 100N were 0.05mm±0.03SD (headed metal), 0.15mm±0.16SD (headless metal) and 0.29mm±0.11SD (composite) and differed significantly (p< 0.02). Using tolerance limits, the data allowed us to predict that with 95% certainty, displacement in 95% of any sample fixed with a headed metal screw will be below 0.17mm, headless metal screw below 0.84mm, and composite screw below 0.76mm.

Conclusion: Comparing two types of conventional metal screws and a new composite bio-absorbable screw to maintain scaphoid fixation under cyclic loading conditions, we found small average fracture displacements for all three screws. Moreover, even following severe cyclic loading conditions, clinically meaningful displacements of more than 1 mm are highly unlikely for any of the three screws. We therefore conclude that a new bio-absorbable composite screw can serve as an alternative to conventional screws when fixing scaphoid fractures.

Introduction and Aims: Limb salvage surgery for the pediatric patient poses unique surgical challenges for the orthopaedic oncologist. In the past, surgeons have advocated amputation or rotationplasty as treatment for the skeletally immature child with a malignant bone tumor that involves a major growth plate and has an expected limb length discrepancy.

Method: The Repiphysis is a non-invasively expandable prosthesis. Applications for the knee joint are approved and other joints are pending. The expansion principle involves energy stored in a spring compressed by a locking system. Lengthenings are achieved via exposure to an electromagnetic field that allows controlled release of the spring and can be done without general anesthesia. Numerous small expansions (5–10mm) keep pace as the child grows. Between 1998–2002, 25 prostheses [knee (19), shoulder (five), hip (one)] were implanted in 21 patients. Most were implanted at the time of tumor resection and nine were revisions from previous reconstruction or fusion.

Results: Ninety lengthenings were performed with all but two on an outpatient basis. An average of 5mm was obtained per lengthening (range 1–35mm). The average follow-up was 25 months (range 12–48 months) and the latest Musculoskeletal Tumor Society functional scores averaged 87%. Eight revisions were required for mechanical problems or stem loosening. There was one amputation caused by post-operative arterial thrombosis.

Conclusion: This unique prosthesis offers many benefits in maintaining limb-length equality in growing patients. We are optimistic that this technology will prove beneficial to patients with malignant bone tumors as well as patients requiring serial limb lengthening or those with spinal deformities.

Introduction and Aims: To determine whether taurine influences skeletal muscle ischaemia-reperfusion injury in a rat hindlimb model.

Method: Twenty-three rats in five groups were subjected to right hindlimb ischaemia-reperfusion injury. The right femoral vein was exposed and cannulated, and a tourniquet applied to the right hindlimb. The left hindlimb acted as a control in each animal. In group 1 there was no treatment, group 2 had normal saline injected into the femoral vein distal to the tourniquet, group 3 had taurine 200mg/Kg injected distal to the tourniquet, group 4 had taurine 200mg/Kg injected proximal to the tourniquet, and group 5 had taurine 100mg/Kg distally and 100mg/Kg proximally. After ischaemia (four hours) and reperfusion (30 minutes), right and left gastrocnemius biopsies were taken and their contraction strength in response to a standardised electrical impulse was measured.

Results: Histology of all right-sided biopsies confirmed inflammatory changes consistent with ischaemia-reperfusion injury. In groups 1, 2, 4, and 5, the mean contraction strength of the right (ischaemia-reperfusion injury) biopsies was significantly less than that of the left (control) biopsies. In group 3 (taurine distal to the tourniquet) the difference in strength between right and left was an order of magnitude less than in the other groups, and was not statistically significant.

Conclusion: These data suggest that taurine during ischaemia confers some protection against ischaemia-reperfusion injury mediated functional impairment in rat skeletal muscle.

Introduction and Aims: The delivery of local antibiotics from a biodegradable implant for orthopedic infections is an attractive alternative. The implant delivers high tissue levels of antibiotic, obliterates dead space, aides in bone repair and does not require removal. This is a review of our clinical experience with custom-made calcium sulfate antibiotic implants (Osteoset BVF®, Wright Medical Technology, Arlington, TN).

Method: Between 12/1996 and 1/2003, 156 procedures using biodegradable beads for orthopaedic infections were performed. Two patients were lost to follow-up. One elderly patient died from post-operative respiratory failure. One patient was lost to follow-up. There were 154 procedures in the analysis group performed on 145 patients (55 female: 90 male). The average age of the population was 45 years (1–85 years). The inclusion in the study required that a patient have an orthopedic infection (osteomyelitis/septic arthritis), which was either biopsy- or culture-proven. The population included 36 patients with a failed arthroplasty, 41 infected nonunions, 50 patients with chronic osteomyelitis, and 27 patients with acute or post-operative bone infections. Patients were treated initially with surgical debridement and insertion of calcium sulfate beads with either Tobramycin and/or Vancomycin. All patients received oral antibiotics or intravenous antibiotics.

Results: Length of follow-up averaged 17 months (six to 67 months). Of the 154 patients, 142 became free of infection (92%). Five patients required multiple surgical procedures involving beads and further debridement to obtain an infection-free status. Many of these patients had an initial attempt at retaining a metal arthroplasty in an initial septic situation. In those patients, infection control required removal of the foreign material. Complete implant degradation occurred in all cases. Five patients had an episode post-operatively of early wound drainage, which was treated with sterile dressing changes while on intravenous antibiotics. In all patients the drainage ceased and the patients did not require further surgery.

Conclusion: Biodegradable calcium sulfate antibiotic implants, along with adjunctive antibiotics, controlled a variety of infections, obliterated dead space and aided in bone repair. Subsequent bone grafting was not required for intramedullary defects due to the osteoconductive properties of calcium sulfate. Biodegradable antibiotic beads appear effective in controlling localised orthopedic infections and do not require a second procedure for removal.

Introduction and Aims: Orthopaedic oncologists are often consulted regarding problems involving salvage of the distal femur due to bone loss, non-unions, infections. In young patients, extensive bony reconstruction is often necessary; in elderly, low demand patients, replacement with an endoprosthetic device results in decreased surgical time and more rapid mobilisation.

Method: Since 1991, 27 patients underwent reconstruction with a custom modular distal femoral replacement and rotating hinged knee joint (DFR). Twenty-two (81%) were revised to a DFR from an existing knee arthroplasty. Diagnoses included fracture, non-union, osteomyelitis, osteolysis or deformity. Average age was 66 (25–85); 83% were female. Most patients had undergone multiple prior surgeries. Patients with a history of infection had undergone aggressive resection and insertion of spacers with prolonged antibiotic administration, however they had no infection at the time of DFR reconstruction. All endoprostheses were cemented. Patients were allowed immediate weight-bearing and rehabilitation similar to patients undergoing TKA.

Results: One elderly patient died in the immediate peri-operative period of respiratory failure and one was lost to follow-up after placement in a nursing home. Average follow-up on 25 evaluable patients was 47 months (7–122). Reoperations were for recurrent infection (six) and tibial component loosening (three). Five of the six with infection were treated with synovectomy, antibiotic beads and suppressive oral antibiotics, and all five devices are still in place at an average of 54 months (range, 25–100). One severely diabetic patient had had multiple episodes of sepsis unrelated to the prosthesis which eventually seeded the distal femur and required a hip disarticulation. MSTS functional scores at last follow-up averaged 49% (13–80%) and HSS knee scores averaged 71% (37–90%).

Conclusion: DFR is a useful salvage procedure in low demand patients. Initially, six patients were scheduled for transfemoral amputation and three were confined to wheelchairs. Patients other than the hip disarticulation were at minimum household ambulators at last follow-up. In spite of problems with infection, most patients improved in overall function.

Surgical outcome has been linked to frequency of the surgical procedure with increased complications among surgeons with low volume. Shoulder arthroplasty is a relatively low volume procedure compared to hip or knee replacement. A recent papers has shown that in 1999 only 3% of surgeons perform 10 or more shoulder arthroplasties in New York State (Hasan SS et al). We postulated that the situation in England and Wales may be similar and examined data on frequency for shoulder hip and knee arthroplasty.

Hospital Episode Statistics(HES) data for the year April 2002 to April 2003 was analysed for Total hip replacement, Elbow replacement and Total and Hemi- shoulder arthroplasty. Consultant codes were matched for surgical codes for the procedures.

338 (61%) of surgeons doing shoulder arthroplasty performed 2 or less procedures during the study year. 13 surgeons (2.4%) performed more than 20 shoulder arthroplasties. This contrasted with shoulder and knee arthroplasty where volumes per consultant were higher (vide infra).

The majority of surgeons who performed shoulder arthroplasty during the year 2002/2003 did 2 procedures or less. The authors raise concern about the outcome of surgery among surgeons with such low volumes.

Compartment syndrome is a unique form of ischaemia of skeletal muscle which occurs despite patency of the large vessels. Decompression allows the influx of activated leucocytes which cause further injury. Vitamin C is a powerful antioxidant which concentrates preferentially in leucocytes and attenuates reperfusion-induced muscle injury. We have evaluated the use of pretreatment with oral vitamin C in the prevention of injury caused by compartment syndrome in a rat cremasteric muscle model.

Acute and delayed effects of pretreatment with vitamin C were assessed at one and 24 hours after decompression of compartment syndrome. Muscle function was assessed electrophysiologically. Vascular, cellular and tissue inflammation was assessed by staining of intercellular adhesion molecule-1 (ICAM-1) and by determination of the activity of myeloperoxidase (MPO) in neutrophils and tissue oedema.

Compartment syndrome impaired skeletal muscle function and increased the expression of ICAM-1, activity of MPO and muscle weight increased significantly. Pretreatment with vitamin C preserved muscle function and reduced the expression of ICAM-1, infiltration of the neutrophils and oedema.

Introduction: The paradoxical further damage done to ischaemic tissue when blood flow and oxygenation are restored is termed ischaemia-reperfusion injury. The underlying mechanisms are complex but centre on oxidative damage to the cell membrane, which suggest a therapeutic role for antioxidants such as endogenous amino acid taurine.

Methods: In this study, 23 rats in 5 groups were subjected to right hind limb ischaemia-reperfusion injury. The right femoral vascular bundle was exposed and the femoral vein cannulated, and a tourniquet applied to the right hind limb. The left hind limb acted as a control in each animal. In group 1 there was no treatment administered, group 2 had normal saline injected into the femoral vein distal to the tourniquet, group 3 had turbine 200mg/Kg injected distal to the tourniquet, group 4 had taurine 200mg/Kg injected proximal to the tourniquet, and group 5 had taurine 100mg/Kg distally and 100mg/Kg proximally. After 4 hours of ischaemia and 30 minutes reperfusion, gastrocnemius biopsies were taken from right and left hind limbs and their contraction strength in response to a standardised electrical impulse was measured.

Results: There was a statistically significant difference in contraction strength between right and left hind limb samples in all groups. The difference in-group 4 was an order of magnitude less than that in groups 1, 2, and 3, with an intermediate value in-group 5. Histological examination confirmed inflammatory changes consistent with ischaemia-reperfusion injury and not simple necrosis.

Conclusion: These data suggest that taurine in the reperfusing blood, rather than in the ischaemic tissues, confers some protection against ischaemia-reperfusion injury mediated functional impairment in rat skeletal muscle.

The purpose of this study was to determine arthroscopically the pathology following anterior shoulder dislocation and assess visually whether rotation of the arm affected the reduction of the capsulolabral complex in cases where this was detached.

Over a sixteen month period from December 2000 to March 2002 we have arthroscoped and followed up prospectively a cohort of thirty patients. All patients were immobilised in a sling for four weeks and rehabilitated in a similar fashion with physiotherapy. The average age of the patients was 31 years and all patients were arthroscoped within six weeks of injury. The Hill Sachs lesion and capsulolabral complex injury were the most common pathology and were seen in two thirds of the patients. In the remaining group capsular tears and stretching were the most frequent injuries seen.

Injuries to the capsulolabral complex were seen in 22 patients. In seventeen of these the capsulolabral complex was still mobile and the time to arthroscopy averaged 10.3 days (Range 0–25). In the remaining five patients the labrum had healed in a malreduced position. The average time to arthroscopy in these patients was 30.8 days (Range 19–42).

In the patients where the capsulolabral complex had not reattached 14/17 (82%) patients demonstrated a better reduction of the labrum onto the glenoid with the arm in external rotation.

Based on these findings we conclude that:

The traditional use of a sling with the arm internally rotated may contribute to the capsulolabral complex healing in a malreduced position. This may be a contributory factor to the high redislocation rates found in young adults. Splinting the arm in a position of external rotation for four weeks may allow better reduction of the capsulolabral complex onto the glenoid.

Matsen in 1975 described Compartment Syndrome (CS) as a condition in which the circulation and function of tissues within a closed space are compromised by increased pressure within that space. Raised intra-compartmental pressures result in progressive venous obstruction, capillary stagnation and microvascular hypoxia.

N-acetyl cysteine (NAC) is an anti-oxidant used clinically to reduce liver injury following paracetamol overdose. NAC has been shown previously to reduce lung injury following exposure to endotoxin. Our aim was to evaluate the efficacy of n-acetyl cysteine in the prevention of CS induced acute muscle injury.

Sprague-Dawley rats (n=6/group) were randomised into Control, CS and CS pre-treated with N-Acetyl Cysteine (0.5g/kg i.p. 1 hr prior to induction). Cremasteric muscle was isolated on its neuro-vascular pedicle and CS injury was induced by placing the muscle in a specially designed pressure chamber. Arterial blood pressure was measured via a cannula placed in the carotid artery. To induce compartment syndrome chamber pressure was maintained at diastolic-10 mm Hg. After three hours pressure was released stimulating surgical fasciotomy. One hour after decompression muscle function was assessed by electrical field stimulation: peak twitch (PTV) and maximum tetanus (MTV) values were recorded. Tissue oedema was assessed by wet to dry ratio (WDR).

Compartment Syndrome (CS) resulted in a significant decrease in muscle function (PTV, MTV). CS also resulted in a significant increase in tissue oedema (WDR). Pre-Treatment with N-Acetyl Cysteine attenuated CS injury as assessed by these parameters. These data show that administration of the anti-oxidant N-Acetyl Cysteine results in significant attenuation of the muscle injury and oedema caused by Compartment Syndrome.

This work was supported by a grant from the Cappagh Trust.

Following ischaemia-reperfusion (I-R) tissues undergo a neutrophil mediated oxidant injury. Vitamin C is a water-soluble endogenous anti-oxidant, which has been shown in previous studies to abrogate neutrophil mediated endothelial injury. Our aim was to evaluate Vitamin C supplementation in the prevention of I-R induced acute muscle injury.

Sprague-Dawley rats (n-6/group) were randomised into control, I-R and I-R pretreated with Vitamin C (3.3g over 5 days). Cremasteric muscle was isolated on its neuro-vascular pedicle and I-R injury induced by clamping the pedicle for 3 hours, the tissue was subsequently reperfused for 60 minutes. Following reperfusion muscle function was assessed by electrical field stimulation: peak twitch (PTV), maximum tetanus (MTV) and fatigability values were recorded. Tissue neutrophil infiltration was assessed by tissue myeloperoxidase (MPO) activity and tissue oedema by wet:dry ratio (WDR).

Ischaemia-reperfusion (I-R) resulted in a significant decrease in muscle function (PTV< MTV) there was no difference in fatigability values between groups. I-R also resulted in a significant increase in neutrophil infiltration (MPO) and tissue oedema (WDR). Pre-treatment with Vitamin C attenuated I-R injury as assessed by these parameters. This data suggests that oral Vitamin C reduce I-R induced acute muscle injury, possibly by attenuating neutrophil mediated tissue injury.

Ischaemia-reperfusion injury (IRI) is caused by endothelial and subendothelial damage by neutrophil-derived oxidants. Vitamin C is an antioxidant which attenuates endothelial injury after IRI. Our aim was to evaluate the effect of oral vitamin C in the prevention of IRI in skeletal muscle. We used a model of cross-clamping (3 hours) and reperfusion (1 hour) of the cremaster muscle in rats. Muscle function was assessed electrophysiologically by electrical field stimulation. Infiltration by neutrophils was determined by the activity of tissue myeloperoxidase (MPO) and tissue oedema by the wet-to-dry ratio. Neutrophil respiratory burst activity was measured in control animals and groups pretreated with vitamin C.

IRI significantly decreased muscle function and increased muscle neutrophil MPO activity and muscle oedema. Pretreatment with vitamin C preserved muscle function and reduced tissue oedema and neutrophil infiltration. Neutrophil respiratory burst activity was reduced in the group treated with vitamin C compared with the control group.

We conclude that pretreatment with oral vitamin C protects against acute muscle IRI, possibly by attenuating neutrophil respiratory burst activity.