Radiographic assessment of distal femur cemented stems in tumor endoprostheses.

BACKGROUND: Distal femoral endoprosthesis (DFE) has become the optimal method of reconstruction in the skeletally mature patients treated for malignant bone tumor. Albeit literature has reported wide range of aseptic loosening in cemented components (6-32%), few authors showed that cement was not detrimental to long-term success of primary distal femoral implants possibly relating to cementing technique. METHODS: A series of consecutive of DFE (MRS and GMRS, Styker Orthopaedics, Mahwah, NJ) was retrospectively reviewed for evidence of loosening on plain radiographs. All prostheses had the standard straight 127-mm stem and a cemented polyethylene tibial component. Cementing technique involved reaming line to line to the selected stem size and cementing without pressurization. Radiographs were assessed by two independent blinded reviewers and scored for radiolucent zones (>1 mm) and graded as not loose, possibly, probable and definite loose. Furthermore, the final reamer/stem diameters, length of resection, tumor type, adjuvant treatment modalities, bushing exchange/revision surgery and infection rate were recorded. RESULTS: There were 70 patients and none were lost to follow-up. The average radiographic follow-up was 7.2 years (58% had f/u >5 years). Examiner A found 89% of femoral components to be "Not Loose" and 11% (n = 6) "Possibly Loose". Examiner B found 96% of femoral components to be "Not Loose" and 4% (n = 2) to be "Possibly Loose". No components scored as probably or definitely loose. Two DFE stems were reported as "Possibly Loose" by both reviewers. No femoral stem required revisions for either loosening, femur fracture or metal failure. Although infection was frequent, there was no septic loosening. CONCLUSION: Despite our study limitations, no radiographic evidence of loosening was found. Cementing distal femur prosthesis with a tight canal fit and with a thin and inconsistent cement mantle appears to be a viable option at short and medium term.

The inter-rater reliability of the diagnosis of surgical site infection in the context of a clinical trial.

OBJECTIVES: The diagnosis of surgical site infection following endoprosthetic reconstruction for bone tumours is frequently a subjective diagnosis. Large clinical trials use blinded Central Adjudication Committees (CACs) to minimise the variability and bias associated with assessing a clinical outcome. The aim of this study was to determine the level of inter-rater and intra-rater agreement in the diagnosis of surgical site infection in the context of a clinical trial. MATERIALS AND METHODS: The Prophylactic Antibiotic Regimens in Tumour Surgery (PARITY) trial CAC adjudicated 29 non-PARITY cases of lower extremity endoprosthetic reconstruction. The CAC members classified each case according to the Centers for Disease Control (CDC) criteria for surgical site infection (superficial, deep, or organ space). Combinatorial analysis was used to calculate the smallest CAC panel size required to maximise agreement. A final meeting was held to establish a consensus. RESULTS: Full or near consensus was reached in 20 of the 29 cases. The Fleiss kappa value was calculated as 0.44 (95% confidence interval (CI) 0.35 to 0.53), or moderate agreement. The greatest statistical agreement was observed in the outcome of no infection, 0.61 (95% CI 0.49 to 0.72, substantial agreement). Panelists reached a full consensus in 12 of 29 cases and near consensus in five of 29 cases when CDC criteria were used (superficial, deep or organ space). A stable maximum Fleiss kappa of 0.46 (95% CI 0.50 to 0.35) at CAC sizes greater than three members was obtained. CONCLUSIONS: There is substantial agreement among the members of the PARITY CAC regarding the presence or absence of surgical site infection. Agreement on the level of infection, however, is more challenging. Additional clinical information routinely collected by the prospective PARITY trial may improve the discriminatory capacity of the CAC in the parent study for the diagnosis of infection.Cite this article: J. Nuttall, N. Evaniew, P. Thornley, A. Griffin, B. Deheshi, T. O'Shea, J. Wunder, P. Ferguson, R. L. Randall, R. Turcotte, P. Schneider, P. McKay, M. Bhandari, M. Ghert. The inter-rater reliability of the diagnosis of surgical site infection in the context of a clinical trial. Bone Joint Res 2016;5:347-352. DOI: 10.1302/2046-3758.58.BJR-2016-0036.R1.

Using a family history questionnaire to identify adult patients with increased genetic risk for sarcoma.

BACKGROUND: Sarcomas in adults can be associated with hereditary cancer syndromes characterized by early-onset predisposition to numerous types of cancer. Because of variability in familial presentation and the largely unexplained genetic basis of sarcomas, ascertainment of patients for whom a genetics evaluation is most indicated poses challenges. We assessed the utility of a Sarcoma Clinic Genetic Screening (scgs) questionnaire in facilitating that task. METHODS: Between 2008 and 2012, 169 patients (median age: 53 years; range: 17-88 years) completed a self-administered scgs questionnaire. A retrospective chart review was completed for all respondents, and descriptive statistics were reported. Probands were divided into two groups depending on whether they did or did not report a family history of Li-Fraumeni syndrome-type cancers. RESULTS: A family history of cancer (as far as 3rd-degree relatives) was reported in 113 of 163 sarcoma patients (69%). Eeles Li-Fraumeni-like (lfl) criteria were fulfilled in 46 probands (28%), Chompret lfl in 21 (13%), Birch lfl in 8 (5%), and classic Li-Fraumeni in none. In the 10 probands tested for TP53 mutations, 1 pathogenic mutation was found. Further investigation of selected families led to the discovery of germline mutations in MLH1, MSH2, and APC genes in 3 individuals. CONCLUSIONS: The scgs questionnaire was useful for ascertaining probands with sarcoma who could benefit from a genetic assessment. The tool allowed us to identify high-risk families fitting the criteria for lfl and, surprisingly, other hereditary cancer syndromes. Similar questionnaires could be used in other cancer-specific clinics to increase awareness of the genetic component of these cancers.

Fire and explosion hazards related to the industrial use of potassium and sodium methoxides.

Sodium and potassium methoxides are used as an intermediary for a variety of products in several industrial applications. For example, current production of so called "1G-biodiesel" relies on processing a catalytic reaction called "transesterification". This reaction transforms lipid resources from biomass materials into fatty acid methyl and ethyl esters. 1-G biodiesel processes imply the use of methanol, caustic potash (KOH), and caustic soda (NaOH) for which the hazards are well characterized. The more recent introduction of the direct catalysts CH3OK and CH3ONa may potentially introduce new process hazards. From an examination of existing MSDSs concerning these products, it appears that no consensus currently exists on their intrinsic hazardous properties. Recently, l'Institut National de l'Environnement Industriel et des Risques (France) and the Canadian Explosives Research Laboratory (Canada) have embarked upon a joint effort to better characterize the thermal hazards associated with these catalysts. This work employs the more conventional tests for water reactivity as an ignition source, fire and dust explosion hazards, using isothermal nano-calorimetry, isothermal basket tests, the Fire Propagation Apparatus and a standard 20 L sphere, respectively. It was found that these chemicals can become self-reactive close to room temperature under specific conditions and can generate explosible dusts.

Hyperthermic isolated limb perfusion for extremity soft tissue sarcomas: systematic review of clinical efficacy and quality assessment of reported trials.

BACKGROUND AND OBJECTIVES: Extremity soft tissue sarcomas (STS) are managed with radiotherapy and limb-sparing surgery however aggressive or recurrent cases require amputation. Hyperthermic isolated limb perfusion (HILP) has been proposed as an alternative. Our aim was to systematically review phase II HILP trials, assess tumor response, limb salvage (LS), and quality of scientific publications on this technique. METHODS: We conducted a literature search of electronic databases (MEDLINE, EMBASE, Scopus, Cochrane Library) and clinical trial registries for phase II HILP trials on non-resectable extremity STS. Outcomes of interest were complete response (CR), partial response (PR), and LS rates. Quality of published trials was assessed using a quality checklist. RESULTS: Of 518 patients across 12 studies, 408 had some response (CR or PR), and 428 had the limb spared. Median CR, PR, and LS rates were 31%, 53.5%, and 82.5%, respectively. Median Wieberdink loco-regional toxicity rates were 3.8%, 45.5%, 17%, 1%, and 0% for levels 1-5, respectively. No trial fulfilled either all ideal or essential quality criteria. Seven trials did not include statistical methodology. CONCLUSION: HILP seems effective in treating advanced extremity STS. However, poor publication quality hinders results validity. Technical and methodological standardization, well-designed, multi-institutional trials are warranted.

Inter- and intra-observer variation in soft-tissue sarcoma target definition.

PURPOSE: To evaluate inter- and intra-observer variability in gross tumor volume definition for adult limb/trunk soft tissue sarcomas. PATIENTS AND METHODS: Imaging studies of 15 patients previously treated with preoperative radiation were used in this study. Five physicians (radiation oncologists, orthopedic surgeons and a musculoskeletal radiologist) were asked to contour each of the 15 tumors on T1-weighted, gadolinium-enhanced magnetic resonance images. These contours were drawn twice by each physician. The volume and center of mass coordinates for each gross tumor volume were extracted and a Boolean analysis was performed to measure the degree of volume overlap. RESULTS: The median standard deviation in gross tumor volumes across observers was 6.1% of the average volume (range: 1.8%-24.9%). There was remarkably little variation in the 3D position of the gross tumor volume center of mass. For the 15 patients, the standard deviation of the 3D distance between centers of mass ranged from 0.06 mm to 1.7 mm (median 0.1mm). Boolean analysis demonstrated that 53% to 90% of the gross tumor volume was common to all observers (median overlap: 79%). The standard deviation in gross tumor volumes on repeat contouring was 4.8% (range: 0.1-14.4%) with a standard deviation change in the position of the center of mass of 0.4mm (range: 0mm-2.6mm) and a median overlap of 93% (range: 73%-98%). CONCLUSION: Although significant inter-observer differences were seen in gross tumor volume definition of adult soft-tissue sarcoma, the center of mass of these volumes was remarkably consistent. Variations in volume definition did not correlate with tumor size. Radiation oncologists should not hesitate to review their contours with a colleague (surgeon, radiologist or fellow radiation oncologist) to ensure that they are not outliers in sarcoma gross tumor volume definition. Protocols should take into account variations in volume definition when considering tighter clinical target volumes.

Initial McGill experience with fluorodeoxyglucose pet/ct staging of soft-tissue sarcoma.

BACKGROUND: Soft-tissue sarcoma spreads predominantly to the lung. The frequency with which positron-emission tomography (pet) detects metastases not already obvious by chest computed tomography (ct) or clinical examination is currently unclear. METHODS: We retrospectively identified cases of soft-tissue sarcoma. Ewing sarcoma, rhabdomyosarcoma, and gastrointestinal stromal tumour were excluded, as were cases in which patients underwent imaging for follow-up, response assessment, or recurrence. Patients all had undergone diagnostic chest ct as part of their staging. Directed studies were requested to follow up on abnormal findings in the clinical history or physical examination. All charts and pre-treatment imaging were reviewed retrospectively. RESULTS: From 2004 to 2008, 75 patients met the criteria for the present review. Their median age was 51 years. In 21% of cases, the primary tumour had been removed (by excisional biopsy or unplanned excision) before staging. Of the previously unresected primary tumours, 97% were avid for fluorodeoxyglucose. Of all tumours, 81% were intermediate or high grade (Fédération Nationale des Centres de Lutte Contre le Cancer grades 2-3). The primary tumour was stage T2b in 69% of cases. The most common primary site was a lower extremity (55%). The most common pathologic diagnoses were leiomyosarcoma (21%), liposarcoma (19%), and synovial sarcoma (17%). At the end of staging, 17% of patients were considered to have metastatic disease. Imaging by pet was negative for distant disease in 64 of the 75 cases. In 7 of the 64 cases, metastatic disease was evident on chest ct (negative predictive value: 88%). Imaging by pet was positive in 8 cases, with 5 of those already known to have metastases, 2 having pathologically proven false positives, and 1 being a new finding of a pulmonary metastasis (positive predictive value: 75%). The pet imaging was indeterminate in 3 patients (none of whom subsequently developed metastatic disease). Two incidental benign parotid tumours were found. Overall, only 1 patient was upstaged as a result of pet imaging (1.3%). In addition, pet did not alter the management of patients already know to have M1 disease (no new organ sites identified). CONCLUSIONS: Although pet may be helpful in specific circumstances, routine use of fluorodeoxyglucose pet imaging for detection of metastatic disease as part of the initial staging of soft-tissue sarcoma added little to imaging by chest ct and was unlikely to alter management in our series.

The efficacy of chemical adjuvants on giant-cell tumour of bone. An in vitro study.

Various chemicals are commonly used as adjuvant treatment to surgery for giant-cell tumour (GCT) of bone. The comparative effect of these solutions on the cells of GCT is not known. In this study we evaluated the cytotoxic effect of sterile water, 95% ethanol, 5% phenol, 3% hydrogen peroxide (H(2)O(2)) and 50% zinc chloride (ZnCI(2)) on GCT monolayer tumour cultures which were established from six patients. The DNA content, the metabolic activity and the viability of the cultured samples of tumour cells were assessed at various times up to 120 hours after their exposure to these solutions. Equal cytotoxicity to the GCT monolayer culture was observed for 95% ethanol, 5% phenol, 3% H(2)O(2) and 50% ZnCI(2). The treated samples showed significant reductions in DNA content and metabolic activity 24 hours after treatment and this was sustained for up to 120 hours. The samples treated with sterile water showed an initial decline in DNA content and viability 24 hours after treatment, but the surviving cells were viable and had proliferated. No multinucleated cell formation was seen in these cultures. These results suggest that the use of chemical adjuvants other than water could help improve local control in the treatment of GCT of bone.

Dedifferentiated giant cell tumour of bone in the form of low-grade fibroblastic osteogenic sarcoma: case report of a unique presentation with follow-up.

Giant cell tumour (GCT) of bone is a locally aggressive benign tumour. It can, however, undergo dedifferentiation, either de novo or secondarily after local recurrence or radiation. Whether spontaneously occurring or induced by previous irradiation, this malignant transformation is typically defined as a high-grade anaplastic sarcoma devoid of giant cells. Dedifferentiation of GCT into low-grade-appearing sarcoma has not been reported yet. Here, we describe the first case of dedifferentiated GCT in the appearance of low-grade fibroblastic osteogenic sarcoma with distant bone metastases. This disease progression occurred without previous irradiation. We confirm the aggressive behaviour of this tumour despite the deceptively bland appearance of the malignant component. We also alert others to the importance of recognizing this rare histology to avoid underdiagnosis and subsequent undertreatment.

Recoil effect of the ice hockey stick during a slap shot.

The purpose of this study was to examine the "recoil" effect of the ice hockey stick shaft during a stationary slap shot. Nine male adult subjects (four elite and five recreational) were tested. Their performances were evaluated by simultaneously recording stick movement and internal bending from high-speed digital video (1,000 Hz) and puck acceleration from a triaxial accelerometer positioned inside the puck. In addition, an electrical circuit measured blade-puck contact time. Data were analyzed with a one-way MANOVA for several dependent variables, including final puck velocity, puck acceleration, maximum stick shaft bending (angle and distance deflection), stick shaft angular velocities, blade-puck contact time, and corresponding time events. The results indicate the following. First, blade-puck contact time was greater for the elite than for recreational players (38 +/- 9 ms and 27 +/- 5 ms); however, measures for puck acceleration were essentially the same (63.8 g +/- 9.9 and 61.8 g +/- 19.5). Two, the elite players were able to generate greater puck velocities (120 +/- 18 km/h and 80.3 +/- 11.6 km/h). Three, the recoil timing was found to be reater for elite players (59.8% of blade-puck contact).

Thermal hazard assessment of AN and AN-based explosives.

Ammonium nitrate (AN) is an essential ingredient in most fertilizers. It is also widely used in the commercial explosives industry. In this latter application, it is mostly mixed with fuel oil to form the most popular commercial explosive: ANFO. In both the fertilizer and the explosive industry, aqueous AN solutions (ANS) of various concentrations are processed. These solutions also form the basis of ammonium nitrate emulsion explosives (also called ammonium nitrate emulsions or ANE), which are produced either in bulk or in packaged form. For all these AN-based products, quantities of the order of 20,000kg are being manufactured, transported, stored, and processed at elevated temperatures and/or elevated pressures. Correspondingly, major accidents involving overheating of large quantities of these products have happened in several of these operations. In comparison, convenient laboratory quantities to investigate thermal decomposition properties are generally less than 1kg. As a result, in order to provide information applicable to real-life situations, any laboratory study must use techniques that minimize heat losses from the samples to their environment. In the present study, two laboratory-scale calorimeters providing an adiabatic environment were used: an accelerating rate calorimeter (ARC) and an adiabatic Dewar calorimeter (ADC). Experiments were performed on pure AN, ANFO, various ANS systems, and typical bulk and packaged ANE systems. The effects of sample mass, atmosphere, and formulation on the resulting onset temperatures were studied. A comparison of the results from the two techniques is provided and a proposed method to extrapolate these results to large-scale inventories is examined.

A comparison of skating economy on-ice and on the skating treadmill.

The purpose of this study was to compare skating economy and oxygen uptake (VO2) on-ice and on the skating treadmill (TM). Male varsity hockey players (n = 15, age = 21.0 yr) performed skating tests on a TM and on-ice. The subjects skated for 4 min at each of 3 submaximal velocities (18, 20, and 22 km . h(-1)), separated by 5 min of passive recovery. A VO2max test followed the submaximal tests and commenced at 24 km . h(-1) with the velocity increasing by 1 km . h(-1) every minute until volitional fatigue. VO2 was 39.7, 42.9, 46.0, and 53.4 ml . kg(-1) . min(-1) at 18, 20, 22, and maximum speed (km . h(-1)) on the TM. VO2 was significantly lower (p < .05) 31.5, 36.9, and 42.7 ml . kg(-1) . min(-1) at 18, 20, and 22 km . h(-1) on-ice. The on-ice VO2max (54.7 ml . kg(-1) . min(-1)) was similar to TM. Stride rate, stride length and heart rate (HR) were significantly different on-ice compared to TM. These results show that at submaximal velocities, VO2, HR, and stride rate are higher on TM compared to on-ice. VO2max was similar while HRmax was higher on the skating treadmill compared to on-ice

Function and health status outcomes in a randomized trial comparing preoperative and postoperative radiotherapy in extremity soft tissue sarcoma.

PURPOSE: Morbidity associated with wound complications may translate into disability and quality-of-life disadvantages for patients treated with radiotherapy (RT) for soft tissue sarcoma (STS) of the extremities. Functional outcome and health status of extremity STS patients randomized in a phase III trial comparing preoperative versus postoperative RT is described. PATIENTS AND METHODS: One hundred ninety patients with extremity STS were randomized after stratification by tumor size dichotomized at 10 cm. Function and quality of life were measured by the Musculoskeletal Tumor Society Rating Scale (MSTS), the Toronto Extremity Salvage Score (TESS), and the Short Form-36 (SF-36) at randomization, 6 weeks, and 3, 6, 12, and 24 months after surgery. RESULTS: One hundred eighty-five patients had function data. Patients treated with postoperative RT had better function with higher MSTS (25.8 v 21.3, P <.01), TESS (69.8 v 60.6, P =.01), and SF-36 bodily pain (67.7 v 58.5, P =.03) scores at 6 weeks after surgery. There were no differences at later time points. Scores on the physical function, role-physical, and general health subscales of the SF-36 were significantly lower than Canadian normative data at all time points. After treatment arm was controlled for, MSTS change scores were predicted by a lower-extremity tumor, a large resection specimen, and motor nerve sacrifice; TESS change scores were predicted by lower-extremity tumor and prior incomplete excision. When wound complication was included in the model, patients with complications had lower MSTS and TESS scores in the first 2 years after treatment. CONCLUSION: The timing of RT has minimal impact on the function of STS patients in the first year after surgery. Tumor characteristics and wound complications have a detrimental effect on patient function.

Functional evaluation in distal femoral endoprosthetic replacement for bone sarcoma.

A multicenter study of successfully treated patients (mean age, 36.7 years) with a minimum 1-year followup (average, 35.4 months) after distal femoral endoprosthetic replacement for bone sarcoma was done using the 1987 and 1993 versions of the Musculoskeletal Tumor Society, the Short Form-36, and the Toronto Extremity Salvage Score functional evaluation criteria. Fifty-six patients (28 women and 28 men) fulfilled the criteria. Thirty-one Kotz prostheses (fixed hinge, uncemented) and 25 Modular Replacement System Prostheses (rotating hinge, cemented) were used. Thirty-five patients walked without aids, 19 used a cane, and two used crutches or a walker. The Musculoskeletal Tumor Society 1987 mean score was 28.1. The Musculoskeletal Tumor Society 1993 mean score was 80.4. The Toronto Extremity Salvage Score mean was 81.6. The Short Form-36 Physical Component Score had a mean of 43.2 and Mental Component Score mean of 54.2. The two groups of implants were comparable, except for the length of bone resection. Multivariate regression analysis revealed that patient age, existence of a pathologic fracture, and type of prosthesis all significantly accounted for differences in functional outcome as measured by the Musculoskeletal Tumor Society 1993, the Toronto Extremity Salvage Score, and the Short Form-36 Physical Component Score scales. Although both implants provided satisfactory function, the Musculoskeletal Tumor Society 1993 and the Toronto Extremity Salvage Score results were significantly better with the Modular Replacement System prosthesis. The effect of possible differences among surgeons or institutions was not addressed.

Sciatic nerve resection in the thigh: a functional evaluation.

Patients with a soft tissue malignancy involving the sciatic nerve who present with neurologic loss generally are advised to have an amputation. Twenty patients who underwent limb-sparing procedures with complete resection of the sciatic nerve as treatment for neurofibrosarcomas (12 patients), liposarcomas (four patients), malignant fibrous histiocytomas (two patients), recurrent desmoid tumor (one patient), and epithelioid hemangioendothelioma (one patient) were reviewed retrospectively. The mean age of these nine women and 11 men at the time of surgery was 51 years (range, 28-84 years). The right sciatic nerve was affected in 12 patients. These tumors were large and high grade. A mean of 22 cm of the nerve had to be resected (range, 8-42 cm). Ten patients received preoperative radiotherapy and 16 patients had intraoperative or postoperative radiotherapy. At a mean followup of 35 months (range, 7-97 months), 14 of the 20 patients were alive. Two patients had local recurrences develop (10%), whereas 12 patients had distant metastases. The function of the 10 patients as assessed by the Toronto Extremity Salvage Score averaged 74%. Most patients indicated that walking in the house is not difficult, but walking is compromised as soon as an effort is needed. Four patients walk without a cane, four needed one cane, and two needed two canes. The patients experienced stiffness, a sense of numbness, and premature fatigue. The use of analgesics was infrequent. Generally, patients rated themselves to be mildly to moderately disabled. From this small number of patients, it is shown that a tumor involving the sciatic nerve can be treated by limb-sparing surgery, including complete nerve resection, as an alternative to hip disarticulation or hindquarter amputation because the limb salvage option provides an acceptable functional outcome.

Acute effects of intense interval training on running mechanics.

The aims of this study were to determine if there are significant kinematic changes in running pattern after intense interval workouts, whether duration of recovery affects running kinematics, and whether changes in running economy are related to changes in running kinematics. Seven highly trained male endurance runners (VO2max = 72.3+/-3.3 ml x kg(-1) x min(-1); mean +/- s) performed three interval running workouts of 10 x 400 m at a speed of 5.94+/-0.19 m x s(-1) (356+/-11.2 m x min(-1)) with a minimum of 4 days recovery between runs. Recovery of 60, 120 or 180 s between each 400 m repetition was assigned at random. Before and after each workout, running economy and several kinematic variables were measured at speeds of 3.33 and 4.47 m x s(-1) (200 and 268 m x min(-1)). Speed was found to have a significant effect on shank angle, knee velocity and stride length (P < 0.05). Correlations between changes pre- and post-test for VO2 (ml x kg(-1) x min(-1)) and several kinematic variables were not significant (P > 0.05) at both speeds. In general, duration of recovery was not found to adversely affect running economy or the kinematic variables assessed, possibly because of intra-individual adaptations to fatigue.

Exercise-induced oxyhemoglobin desaturation and pulmonary diffusing capacity during high-intensity exercise.

The purpose of this investigation was to examine if exercise-induced arterial oxyhemoglobin desaturation selectively observed in highly trained endurance athletes could be related to differences in the pulmonary diffusing capacity (DL) measured during exercise. The DL of 24 male endurance athletes was measured using a 3-s breath-hold carbon monoxide procedure (to give DLCO) at rest as well as during cycling at 60% and 90% of these previously determined VO2max. Oxyhemoglobin saturation (SaO2%) was monitored throughout both exercise protocols using an Ohmeda Biox II oximeter. Exercise-induced oxyhemoglobin desaturation (DS) (SaO2% < 91% at VO2max) was observed in 13 subjects [88.2 (0.6)%] but not in the other 11 nondesaturation subjects [NDS: 92.9 (0.4)%] (P < or = 0.05), although VO2max was not significantly different between the groups [DS: 4.34 (0.65) l/min vs NDS: 4.1 (0.49) l/min]. At rest, no differences in either DLCO [ml CO.mmHg-1.min-1: 41.7 (1.7) (DS) vs 41.1 (1.8) (NDS)], DLCO/VA [8.2 (0.4) (DS) vs 7.3 (0.9) (NDS)], MVV [l/min: 196.0 (10.4) (DS) vs 182.0 (9.9) (NDS)] or FEV1/FVC [86.3 (2.2) (DS) vs 82.9 (4.7) (NDS)] were found between groups (P > or = 0.05). However, VE/VO2 at VO2max was lower in the DS group [33.0 (1.1)] compared to the NDS group [36.8 (1.5)] (P < or = 0.05). Exercise DLCO (ml CO.mmHg-1.min-1) was not different between groups at either 60% VO2max [DS: 55.1 (1.4) vs NDS: 57.2 (2.1)] or at 90% VO2max [DS: 61.0 (1.8) vs NDS: 61.4 (2.9)]. A significant relationship (r = 0.698) was calculated to occur between SaO2% and VE/VO2 during maximal exercise. The present findings indicate that the exercise-induced oxyhemoglobin desaturation seen during submaximal and near-maximal exercise is not related to differences in DL, although during maximal exercise SaO2 may be limited by a relatively lower exercise ventilation.