Introduction

Osteochondral lesions (OCLs) of the talus are a challenging and increasingly recognized problem in chronic ankle pain. Many novel techniques exist to attempt to treat this challenging entity. Difficulties associated with treating OCLs include lesion location, size, chronicity, and problems associated with potential graft harvest sites. Matrix associated stem cell transplantation (MAST) is one such treatment described for larger lesions >15mm2 or failed alternative therapies. This cohort study describes a medium-term review of the outcomes of talar lesions treated with MAST.

Despite considerable legacy issues, Girdlestone's Resection Arthroplasty (GRA) remains a valuable tool in the armoury of the arthroplasty surgeon. When reserved for massive lysis in the context of extensive medical comorbidities which preclude staged or significant surgical interventions, and / or the presence of pelvic discontinuity, GRA as a salvage procedure can have satisfactory outcomes. These outcomes include infection control, pain control and post-op function. We describe a case series of 13 cases of GRA and comment of the indications, peri, and post-operative outcomes.

We reviewed all cases of GRA performed in our unit during an 8 year period, reviewing the demographics, indications, and information pertaining to previous surgeries, and post op outcome for each. Satisfaction was based on a binary summation (happy/unhappy) of the patients’ sentiments at the post-operative outpatient consultations.

13 cases were reviewed. They had a mean age of 75. The most common indication was PJI, with 10 cases having this indication. The other three cases were performed for avascular necrosis, pelvic osteonecrosis secondary to radiation therapy and end stage arthritis on a background of profound learning disability in a non-ambulatory patient. The average number of previous operations was 5 (1-10). All 13 patients were still alive post girdlestone. 7 (54%) were satisfied, 6 were not. 3 patients were diabetic. 5 patients developed a sinus tract following surgery.

With sufficient pre-op patient education, early intensive physiotherapy, and timely orthotic input, we feel this procedure remains an important and underrated and even compassionate option in the context of massive lysis and / or the presence of pelvic discontinuity / refractory PJI. GRA should be considered not a marker of failure but as a definitive procedure that gives predictability to patients and surgeon in challenging situations.

A concern of metal on metal hip resurfacing arthroplasty is long term exposure to Cobalt (Co) and Chromium (CR) wear debris from the bearing. This study compares whole blood metal ion levels from patients drawn at one-year following Birmingham Hip Resurfacing (BHR) to levels taken at a minimum 10-year follow-up.

A retrospective chart review was conducted to identify all patients who underwent a BHR for osteoarthritis with a minimum 10-year follow-up. Whole blood metal ion levels were drawn at final follow-up in June 2019. These results were compared to values from patients with one-year metal ion levels.

Of the 211 patients who received a BHR, 71 patients (54 males and 17 females) had long term metal ion levels assessed (mean follow-up 12.7 +/− 1.4 years). The mean Co and Cr levels for patients with unilateral BHRs (43 males and 13 females) were 3.12 ± 6.31 ug/L and 2.62 ± 2.69 ug/L, respectively, and 2.78 ± 1.02 ug/L and 1.83 ± 0.65 ug/L for patients with bilateral BHRs (11 males and 4 females). Thirty-five patients (27 male and 8 female) had metal-ion levels tested at one-year postoperatively. The mean changes in Co and Cr levels were 2.29 ug/l (p = 0.0919) and 0.57 (p = 0.1612), respectively, at one year compared to long-term. These changes were not statistically significant.

This study reveals that whole blood metal ion levels do not change significantly when comparing one-year and ten-year Co and Cr levels. These ion levels appear to reach a steady state at one year.

Our results also suggest that regular metal-ion testing as per current Medicines and Healthcare products Regulatory Agency (MHRA) guidelines may be impractical for asymptomatic patients. Metal-ion levels, in and of themselves, may in fact possess little utility in determining the risk of failure and should be paired with radiographic and clinical findings to determine the need for revision.

Osteochondral lesions (OCLs) of the talus are a challenging and increasingly recognized problem in chronic ankle pain. Many novel techniques exist to attempt to treat this challenging entity. Difficulties associated with treating OCLs include lesion location, size, chronicity and problems associated with potential graft harvest sites. Matrix associated stem cell transplantation (MAST) is one such treatment described for larger lesions >15mm² or failed alternative therapies. This cohort study describes a 5 year review of the outcomes of talar lesions treated with MAST. A review of all patients treated with MAST by a single surgeon was conducted. Pre-operative radiographs, MRIs and FAOS outcome questionnaire scores were conducted. Intraoperative classification was conducted to correlate with imaging. Post-operative outcomes included FAOS scores, return to sport, revision surgery/failure of treatment and progression to arthritis/fusion surgery. 32 patients were identified in this cohort. There were 10 females, 22 males, with an average age of 35. 01. 73% had returned and continued playing active sport. 23 patients underwent MAST in the setting of a failed previous operative attempt, with just 9 having MAST as a first option. 9 patients out of 32 had a further procedure. Two patients had a further treatment directed at their OCL. Two patients had a fusion, 2 had a cheilectomy at > 4 years for impingement, one had a debridement of their anterolateral gutter, one had debridement for arthrofibrosis, one patient had a re alignment calcaneal osteotomy with debridement of their posterior tibial tendon. MAST has demonstrated positive results in lesions which prove challenging to treat, even in a “failed microfracture” cohort.

Recent studies have shown that bone mineral distribution is more heterogeneous in bone tissue from an animal model of osteoporosis and osteoporotic human vertebral trabeculae. These tissue alterations may play a role in bone fragility seen in osteoporosis, albeit that they are not detectable by current diagnostic techniques (dual-energy X-ray absorptiometry, DXA). Type II Diabetes Mellitus (T2DM) also increases a patient's fracture risk beyond what can be explained or diagnosed by DXA, and is associated with impaired bone cell function, compromised collagen structure and reduced mechanical properties. However, it is not currently known whether osteoporosis or T2DM leads to an increased mineral heterogeneity in the femoral head of humans, a common osteoporotic fracture site. In this study, we examine bone microarchitecture, mineralisation and mechanical properties of trabecular bone from osteoarthritic, diabetic and osteoporotic patients. We report that while osteoporotic trabecular bone has significantly deteriorated mechanical properties and microarchitecture compared to the other groups, there is also a significant increase in mean mineral content. Moreover, the heterogeneity of the mineral content in osteoporotic bone is significantly higher than osteoarthritic (+35%) and diabetic (+13%) groups. We propose that the compromised architecture following bone loss at the onset of osteoporosis alters the mechanical environment, which initiates compensatory changes in mineral content. We show for the first time that trabecular bone mineralisation is significantly more heterogeneous (+20%) in T2DM compared to osteoarthritic controls. Interestingly, bone microarchitecture and mechanical properties are not significantly different between diabetic and osteoarthritic groups despite this increase in mineral heterogeneity.

The goal of surgery for osteochondral lesions is to regenerate the damaged cartilage with ideally hyaline cartilage. The current gold standard treatment is bone marrow stimulation (BMS) by microfracture. In reality however BMS typically results in the generation of fibrocartilage. Orthobiologics including bone marrow aspirate, platelet rich plasma and hyaluronic acid products have been shown to promote cartilage healing and potentially increase the formation of hyaline cartilage in treated lesions. However the role of these products, the timing of their administration and frequency of application are still not clearly defined and their routine use is still not recommended. These issues and future directions for research and future clinical application will be discussed.

Introduction

Ischaemia reperfusion injury (IRI) is a very common metabolic insult in orthopaedics. It is often a subtle clinical event such as after brief tourniquet use, however severe injury, even multi-organ failure or death may result from prolonged tourniquet-use, crush injuries, vascular trauma or the release of compartment-syndrome. IRI is mediated by leukocyte infiltration and oxidatively-induced endothelial disruption. Antioxidants clearly attenuate or prevent this effect in animal models.

Introduction

Nonagenarian patients with hip fractures present many challenges to the clinician, both in terms of their advanced age and medical co-morbidities with potential orthopaedic complications. Our aims were to assess outcome of hip fractures in a nonagenarian population with respect to pre-operative predictors of outcome, immediate and long-term morbidity, and survival rates.

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.

Introduction: Ischaemia-reperfusion-injury (IRI) is one of the most common metabolic insults in orthopaedic practice. It is often a mild insult after brief tourniquet use with minimal clinical implications; but much more severe insults may result from excessive tourniquet-times, vascular trauma or release of compartment-syndrome. It is mediated largely by oxidatively-induced endothe-lial disruption and leukocyte infiltration. Antioxidants attenuate or prevent this effect in animal models.

Hypothesis: That IRI can be attenuated using established antioxidant medications (ascorbate and n-acetyl-cysteine) in the controlled setting of elective knee arthroscopy.

Methods: A EudraCT registered, prospective, randomized-controlled trial was performed. Patients (n=24) undergoing elective knee arthroscopy were randomized to one of 3 groups (IV NAC/oral ascorbate/placebo). Full blood counts, a broad array of cytokines and adhesion molecules, physiological response, pain scores and analgesia were recorded pre-operatively and at 3 postoperative time-points (10mins, 2hours, 4hours).

Results: Physiological response, analgesia and VAS did not differ. Systemic leukocytes and neutrophils were increased (p=0.001) indicating a measurable reperfusion injury. Ascorbate tended to inhibit ICAM-1 (p=0.10) and IFN-gamma (p=0.080). NAC inhibited VCAM-1 (p=0.003) and tended to inhibit ICAM-1 (p=0.094). Selectins responded in a similar pattern but not significantly. NAC tended to increase circulating leukocytes (0.093), neutrophils (0.12) and monocytes (0.04) and also induced a transient early increase in IFN-gamma (p=0.022).

Conclusions: Elevated circulating leukocytes indicate reduced leukocyte trapping and infiltration due to reduced adhesion molecule expression. NAC attenuates IRI resulting from tourniquet use in knee arthroscopy. The study was underpowered to confirm the efficacy of ascorbate in this setting. Further studies are necessary on the effects of these substances in more extreme ischaemic insults in which they may confer significant local and systemic benefits for the patient. Ascorbate and NAC act at different points in the inflammatory cascade and their potential synergistic effects warrant investigation.

Introduction: The high prevalence and associated morbidity of the hallux valgus deformity has lead to a myriad treatment options being developed. These range from conservative to operative interventions, including many different forms of osteotomy. The various interventions have met with mixed success, with some operative options suffering a high level of recurrence or patient dissatisfaction. Both outcomes have been shown to correlate to inadequate correction of one or other component of the deformity. High recurrence rates result most frequently from the failure to correct for both the intermetatarsal (IMA) and the distal metatarsal-articular (DMAA) angles, instead focusing on the IMA alone. In most techniques, the use of a two-dimensional osteotomy with a concentric axis of rotation allows only for the correction of one of the involved angles, therefore is not appropriate for the correction of this geometrically complex condition. This most often results in failure to adequately correct the DMAA. The scarf osteotomy is a triplanar osteotomy with the potential to correct both the DMAA and IMA in the same procedure, thereby performing a more anatomical correction.

Hypothesis: Even in experienced hands the accuracy of the correction can be improved, and the limitations of attainable correction identified, with simple calculations based on pre-operative radiographs.

Methods: We generated a formula to calculate the appropriate proximal and distal translations required for a given length of osteotomy to accurately correct the deformities. Two groups, of 20 patients each, were included in the study. One group prior to introduction of the formula and a second group after the introduction of the formula. Pre and post-operative weight bearing radiographs were assessed by blinded observers pre and post-operatively to determine the accuracy of the formula. Groups were compared using the independent samples T-test.

Results: There were no differences between the pre-operative IM and DMA angles between the groups. Post operative DMAA was improved by 6.1 degrees when using the formula (p=0.02). The frequency of post-operative IMA correction to within normal limits improved from 75% to 100% and the average IMA correction was improved by 2.5 degrees (p=0.003). Post operative IM and DMA angles correlated well with the calculated results from the formula. This formula has altered procedure selection in our institution for certain patients with combined large DMA and IM angles due to the easy pre-operative identification of the limits of correction.

Discussion and Conclusion: The formula allows more precise, reproducible correction of both the IMA and DMAA. The formula also clarifies the limits of the scarf osteotomy and therefore improves appropriate patient selection.

Objectives: Ischaemia reperfusion injury (IRI) is one of the most common metabolic insults in orthopaedic clinical practice. Oral ascorbate and both oral and intravenous n-acetylcysteine (NAC) have shown definitive beneficial effects in animal skeletal muscle IRI models. The authors hypothesized that a similar protective effect could be demonstrated in a well designed clinical trial.

Materials and Methods: A EudraCT registered, prospective, randomized, controlled, double blind trial was performed to assess the hypothesis. Ethical approval was obtained from the competent authority. Patients (n=18) undergoing elective knee arthroscopy were randomised to one of 3 groups. The NAC group received IV NAC and preoperative oral placebo. The ascorbate group received oral ascorbate and IV placebo. The placebo group received both oral and IV placebo. Anaesthetic protocols were standardized across all groups. Phlebotomy was performed preoperatively and at 3 post-operative time points. IL-1, 2, 6 and 10, ICAM, VCAM, Selectins, TNF-alpha and malondialdehyde (MDA) were measured in systemic and local blood samples. Physiological parameters were recorded in the peri-operative period. Post-operative analgesic requirements and visual analogue scores were recorded. Leg oedema was measured using volumetric analysis and figure-of-eight tape measurement.

Results: There were no differences between the groups pre-operatively. In the post-operative period the analgesic requirements were lower in the NAC group compared to ascorbate and placebo groups. CRP and d-dimers were found to peak in the early post operative period. White cell counts decreased in all groups in the early post-operative period, with a lesser reduction in the NAC and ascorbate groups. Elevation of MDA was noted in all groups but was significantly less in the NAC group. There was a trend towards increasing IL-6 and IL-8. There was a trend towards decreasing TNF-alpha and IL-1.

Conclusions: Ascorbate and NAC appear to attenuate the inflammatory response to IRI in a clinical model. These cheap, readily available medications which are acceptable to patients and doctors alike appear offer a potential benefit to patients. Further studies are required to clarify the extent of the benefit and to examine the role of these medications in trauma and in the setting of more extensive ischaemic insults.

Ankle intra-articular pathology after acute injury is common and often under-diagnosed. While the majority of soft tissue injuries improve with rehabilitation, up to 40% of patients experience chronic pain, stiffness or instability. MRI is increasingly used in the investigation of such patients; however interpretation of MRI findings requires specialist expertise. The aim of this study was to determine the diagnostic potential of magnetic resonance imaging (MRI) compared to ankle arthroscopy.

Forty consecutive patients presenting with ankle pain of at least three months duration were included in the study. This cohort of patients underwent magnetic resonance imaging (MRI) and then arthroscopy.

Pre-operative MRI reported findings were compared with the arthroscopic findings. The sensitivity, specificity, positive and negative predictive value of MRI for diagnosing ankle pathology was then assessed. The 2 senior authors reviewed the MRI scans and their findings correlated.

The average time between injury and presentation to our service was 2.2 years. This interval ranged from 3 months to 10 years. 51% of patients gave history of inversion and/or plantar flexion injuries. 14 % had symptoms, which persisted following an ankle fracture. At arthroscopic evaluation 23 patients had osteochondral defects and 37 had evidence of synovitis. MRI identified 50% of the osteochondral defects with sensitivity 50% and specificity 100%. Synovitis was not identified in any of the patients on preoperative MRI but 33% of the preoperative MRI did demonstrate a joint effusion.

Despite the high rate of discordance between MR imaging and arthroscopy in our study MRI still remains a useful adjunct in the investigation of ankle pain. The implications for practice and further study are discussed.

Ankle intra-articular pathology after acute injury is common and often under-diagnosed. While the majority of soft tissue injuries improve with rehabilitation, up to 40% of patients experience chronic pain, stiffness or instability. MRI is increasingly used in the investigation of such patients; however interpretation of MRI findings requires specialist expertise. The aim of this study was to determine the diagnostic potential of magnetic resonance imaging (MRI) compared to ankle arthroscopy.

Forty consecutive patients presenting with ankle pain of at least three months duration were included in the study. This cohort of patients underwent magnetic resonance imaging (MRI) and then arthroscopy.

Pre-operative MRI reported findings were compared with the arthroscopic findings. The sensitivity, specificity, positive and negative predictive value of MRI for diagnosing ankle pathology was then assessed. The 2 senior authors reviewed the MRI scans and their findings correlated.

The average time between injury and presentation to our service was 2.2 years. This interval ranged from 3 months to 10 years. 51% of patients gave history of inversion and/or plantar flexion injuries. 14 % had symptoms, which persisted following an ankle fracture. At arthroscopic evaluation 23 patients had osteochondral defects and 37 had evidence of synovitis. MRI identified 50% of the osteochondral defects with sensitivity 50% and specificity 100%. Synovitis was not identified in any of the patients on preoperative MRI but 33% of the preoperative MRI did demonstrate a joint effusion.

Despite the high rate of discordance between MR imaging and arthroscopy in our study MRI still remains a useful adjunct in the investigation of ankle pain. The implications for practice and further study are discussed.

Abstract: Plantar fasciitis is the most common cause of heel pain for which medical care is sought. It is associated with significant morbidity placing activity limitations on the patients. The response of plantar fasciitis to any treatment is unpredictable. Many different modalities of treatment are used in its management. Injection of plantar fascia with local anaesthetic and steroids under general anaesthesia was carried out in 50 patients who had a clinical diagnosis of plantar fasciitis of greater than 3 month duration. Following induction of general anesthesia, a 20-gauge needle was guided toward and into the plantar fascia. 5mls of local anaesthetic and steroid was injected into the proximal plantar fascia. The patients were followed up over a mean of 6 months. Pain intensity was graded on an 11-point visual analog scale (VAS). Questionnaires with the VAS were filled out after treatment to determine the effectiveness of the procedure. The mean pain score decreased by 5.4 points. There were no complications during or after the procedure. Patients were questioned in relation to their occupational, athletic and recreational activities pre and post the injection.

Injection of the plantar fascia under general anaesthesia is a safe and effective method for the relief of conservatively unmanageable heel pain due to plantar fasciitis. A larger patient population and a greater than 1 year follow up would be helpful to determine the long term benefits & outcomes of this treatment.

The purpose of this study was to analyse the twenty to twenty-five year outcomes of one hundred and ninetyfive cemented, matte finish, HD-2 THRs performed in one hundred and sixty-six patients with osteoarthritis of the hip by two surgeons.

The one hundred and ninety-five THRs (one hundred and sixty-six patients) were followed prospectively by clinical assessment using the Harris Hip Score (HHS) and radiographic analysis.

One hundred and forty-nine patients (90%) died with their implant still functioning or still had a successful implant at twenty to twenty-five years follow-up. Ten patients (6%) underwent a revision for aseptic loosening of the acetabular (n=2, 1.2%) or femoral (n=4, 2.4%) component, or both (n=4, 2.4%), that was related to wear-induced osteolysis. 7 (4.2%) patients (eight hips) were lost to follow-up. The mean HHS at the latest follow-up (twenty to twenty-five years) was 88±9. Radiographically, twenty-nine (85%) of the acetabular components were well fixed and four (12%) were probably or possibly loose. Two hips (6%) had probable or possible loosening of the femoral component. At twenty five years, the calculated cumulative survival rate (Kaplan-Meier method) revealed excellent results for revisions (83%±6, any cause) and aseptic loosening (86%±6, femoral component, 93%±3, acetabular component).

The surviving patients had a good mean follow-up and radiographic fixation, proving the exceptional long-term success of this implant.

With the increasing availability of magnetic resonance imaging, there is potentially less emphasis being placed on making a definitive clinical diagnosis. Changes in the undergraduate curriculum have also reduced the emphasis on orthopaedic clinical evaluation. This aim of this study was to evaluate the predictability of clinical examination alone in comparison with arthroscopic findings in 50 consecutive patients presenting for arthroscopy to our service. Four trainees examined each patient; each examiner was blinded to the clinical diagnosis made by their colleagues. All patients were examined in the ward and subsequently underwent examination under anaesthesia and arthroscopy.

Of the tests for meniscal injuries joint line tenderness was the most sensitive (77%) and specific (68%). Apley’s and McMurray’s test while specific (92%, 98%) lacked sensitivity (9%, 30%). Overall the tests for anterior cruciate ligament (ACL) disruption were more reliable than the tests for meniscal injuries. The anterior drawer and Lachmann tests had high specificity (90%, 75%) and sensitivity. The pivot shift test also had very high specificity (75%) and sensitivity (98%) for detecting ACL injuries. These data demonstrate that joint line tenderness is the most reliable sign of menis-cal injury. In the absence of joint line tenderness Apley & McMurray’s tests have little role in routine clinical examination. Clinical tests and signs of ACL deficiency are consistently reliable in diagnosing ACL rupture.

Background: Nonagenarian patients with hip fractures present many challenges to the clinician, both in terms of their advanced age and medical co-morbidities with potential orthopaedic complications. Our aims were to assess outcome of hip fractures in a nonagenarian population with respect to pre-operative predictors of outcome, immediate and long-term morbidity, and survival rates.

Methods: All nonagenarian patients with a hip fracture admitted to our unit between January 2000 and Decem-ber 2003 were considered. Eighty-one patients were included, the majority being female (M: F 14: 67). Ages ranged from 90 to 98 years for female patients (mean 92.5 years, SD 2.2) compared to 90 to 95 years for male patients (mean 92.7 years, SD 2).

Results: Delay to surgery was 1.25 days and the median ASA grade was III. The method of anaesthesia used was spinal in 78% and general in 22%. The majority of patients had intertrochanteric fractures and methods of fixation involved internal fixation in 63% and hemiarthroplasty in the remaining 36% of the group deemed fit for surgery. The rate of complications during inpatient stay was 19% and there were eight in-patient post-operative mortalities due to medical complications. Mean survival post hip fracture in our patient group was 474.7 days (median 372.5 days). Within forty days of surgery 25% of patients died, including our inpatient mortality of 10%. However, 50% of the patients were still alive 126 days post-operatively.

Conclusion: Hip fractures must be given special attention in the nonagenarian population because of their advanced age and medical co-morbidities. Careful pre-operative assessment and medical maximisation combined with prompt surgical intervention yielded a good outcome and return to pre-injury status for most patients. Lower ASA grades, surgery within 48 hours, and increased pre-operative haemoglobin levels were all associated with favourable outcomes. Medical complications were the major cause of morbidity and mortality with a low rate of orthopaedic complications. The majority of patients were able to return to their previous residence and continued to be mobile with various levels of assistance.

Purpose: Compartment syndrome (CS) is a unique form of skeletal muscle ischaemia. N-acetyl cysteine (NAC) is an anti-oxidant with beneficial microcirculatory effects. We aim to assess the effect of NAC administration on CS induced muscle injury.

Methods: 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 were assessed at24-hours.

Results: 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 24hrs 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).

Conclusions: |NAC provides extended protection to skeletal muscle against compartment syndrome induced injury by both direct reducing neutrophil mediated tissue toxicity and by reducing neutrophil recruitment to the site of injury.

Purpose: The young patient with hip arthritis remains one of the biggest challenges to arthroplasty surgeons. The difficulty of providing a long-lasting total hip arthroplasty (THA) has been clearly documented in the literature. The aim of this study was to assess the outcomes of uncemented THA’s performed in our unit in patients aged under 50.

Methods: In our unit information on all patients is recorded prospectively on an arthroplasty database. From this database we identified 273 uncemented THAs in 237 patients under the age of 50 performed in our unit between 1985 and 2000 with a minimum of 5 year follow up. Outcomes were assessed in terms of 10 and 15-year survival with revision for any reason as the endpoint. Hip scores at routine and most recent follow-up were also reviewed. All surviving implants were radiographically assessed for acetabular wear, component loosening and for the presence of osteolysis.

Results: The mean age of patients at the time of surgery was 41.1 years. 36 patients had bilateral THA. The overall 10 and 15 year survival was 88.7 ± 2.4% and 65.6 ± 4.8 % respectively. Femoral stem survival was significantly higher at 100 % and 98.4 ± 1.6% at 10 and 15 years. Acetabular component survival was 88.6 ± 2.5 % at 10 years and 65.9 ± 4.8 % at 15 years. In unrevised THA’s 56.9% had asymmetric polyethylene wear > 2mm. 2% had definite evidence of acetabular loosening. 25.5% had radiographic evidence of femoral cortical hypertrophy or spot-welds. The mean HHS pre–operatively, at 5 and 10-year follow-up was 46.4 ± 13, 90.7 ± 12.2 and 87.9 ± 14.7 respectively.

Conclusions: Uncemented THA is effective even in young active patients. The main challenges remain ace-tabular polyethylene wear and loosening. Femoral uncemented stems provide long-term functional fixation. Contemporary bearing surfaces in association with such stems may provide long lasting THA’s even in young active patients.