Localized pigmented villonodular synovitis of the anterior cruciate ligament of the knee: an exceptional presentation of a rare disease with neoplastic and inflammatory features.

Pigmented villonodular synovitis (PVNS) is a rare condition, most commonly involving the knee joint. PVNS is locally aggressive and can invade and destroy surrounding soft tissue and bone, leading to anatomical and functional deterioration of the affected joint. Localized PVNS is an unusual presentation of the disease, generally consisting of a nodular lesion protruding into the articular cavity. Localized PVNS of the knee can mimic other joint disorders which may pose a challenge for a correct diagnosis. Given the locally aggressive behavior of PVNS, prompt identification and excision of the lesion are instrumental to avoid complications. Here, we report a rare case of localized cystic PVNS involving the anterior cruciate ligament of the knee in a 32-year-old woman with persistent knee pain, in whom magnetic resonance imaging was inconclusive. The diagnosis was achieved via arthroscopy and histology. We also present a concise review of the literature on this pathological entity as well as a discussion on the differential diagnosis between localized PVNS and other intra-articular cystic lesions.

Collatamp sponges in the management of open fractures.

Open fractures are at high risk of infection and the prompt treatment of these injuries is critical to the success and is crucial to reduce the rate of complications. The basic steps of treatment include the immediate administration of systemic antibiotics, early surgical stabilization of the fracture associated with copious irrigation and radical debridement of the site of exposure, and when possible adequate soft tissue coverage. The systemic antibiotic therapy significantly improves the prognosis and reduces the occurrence of complications. However, in order to ensure adequate and sustained local concentration of antibiotic agent, high doses and for a long time are necessary. This increases the risk of side effects and bacterial resistance. The introduction of the antibiotic-loaded collagen sponges offers the advantages of a high local concentrations of antibiotic carrier delivering system with reduced systemic drug diffusion (less risk of side effects and resistance rate). Sponges are also biodegradable and fully resorbable and do not require additional surgery for their removal.

Bone integration of new stemless hip implants (proxima vs. nanos). A DXA study: preliminary results.

The development of short femoral prostheses has the advantage to preserve bone and soft tissues, restore hip geometry, permit mini-invasive techniques and allow quickly return to an active life, but very few studies described bone reaction to these new designed prostheses. The aim of the present study was to evaluate the osseointegration of two different partial neck retained stemless hip prosthesis at one year after surgery, measured by the changes of periprosthetic bone mineral density (BMD) in 5 regions of interest (ROIs) using a dual-energy X ray absorptiometry (DXA) device. The signs of stress-shielding were evaluated by standard radiographs. Thirty-two uncemented primary total hip arthroplasty (THA) patients allocated into 2 groups were evaluated. In the first group (n=19) a Proxima (De-Puy-J&J) hip stem was implanted. In the second group (n=12) a Nanos (Smith & Nephew) hip stem was used. We found that both the implants preserve metaphyseal bone stock and increase periprosthetic BMD. In Nanos prostheses a significant higher BMD values were observed in region of interest (ROI) 3 and 4 (p<0.05). No differences were found in ROIs 1, 2, and 5. Proxima stem seem to produce a physiological strain distribution in the femur. No signs of stress-shielding were present in both the implants. In conclusion, this preliminary DXA analysis showed a physiological integration of both the stems that reproduces the biomechanical stress of proximal femur. New designed short stem implants showed optimal osseointegration after one year, and therefore appears an excellent alternative to traditional long stem hip prostheses.

Bioplasty for vertebral fractures: preliminary results of a pre-clinical study on goats using autologous modified skin fibroblasts.

The debate is still ongoing about the long term effects of the mininvasive vertebral augmentation techniques and their usefulness in treating more complex cases where a bone inducing effect more than a merely bone substitution would be suitable, such as the vertebral fractures in young patients. We previously developed a clinically relevant gene therapy approach using modified dermal fibroblasts for inducing bone healing and bone formation in different animal models. The aim of this study is to show the feasibility of a minimally invasive percutaneous intrasomatic ex vivo gene therapy approach to treat thoracolumbar vertebral fractures and anterior column bone defects in a goat model.

The use of collatamp in total hip arthroplasty.

Total Hip Arthroplasty (THA) is one of the most common orthopedic operations in the world. The number of THA is expected to grow and with it the number of associated complications. Although improved surgical technique and the development of more scrupulous asepsis has decreased the incidence of periprosthetic joint infection (PJI), it remains one of the most feared complications of joint arthroplasty. The purpose of this study is to present the use of antibiotic-loaded collagen sponges (Collatamp EG) in the prophylaxis and treatment of PJI. For this scope a case report is described. The advantages offered by the antibiotic loaded sponges in terms of high and sustained concentration of antibiotic at the site of infection, diffused by the fully reabsorbable carrier, showed to be a an important adjuvant therapy in the treatment of PJI. Low systemic concentration of the drug and a wide versatility in surgical application are other advantages of this dispositive.

The effect of back belts on lumbar muscle fatigue.

STUDY DESIGN: An experiment was conducted to investigate the effect of wearing a weight lifting belt on the endurance and fatigue characteristics of the extensor muscles of the spine. OBJECTIVE: To evaluate the effectiveness of back belts in preserving the endurance characteristics of the spinal musculature. SUMMARY OF BACKGROUND DATA: Previous studies have investigated the use of back belts in increasing intra-abdominal pressure and thus increasing the stabilization of the spine. Other studies have looked at the association of low back disability and wearing back belts. No study has examined the relationship between wearing back belts and measures of spinal muscle fatigue and endurance. METHODS: Thirteen male industrial workers performed a lifting and lowering task from the floor to a 76.2 cm height at 4.3 min-1 2 days a week for 4 weeks. The load was psychophysically determined and averaged 28.1 kg for a total of 28.9 metric tons moved in 4 hours. Subjects lifted for 1, 2, 3, and 4 hours, respectively, for the first 4 days of the experiment. These were considered training days. During the last 4 days, subjects lifted for 4 hours per day; 2 days with a back belt, and 2 days without a back belt. Maximum isokinetic endurance of the extensors was measured for 50 repetitions (5 sets of 10 repetitions) at the end of 4 hours of lifting. Median frequencies of the electromyographic signal from six locations over the back extensors were measured for 30 seconds at 80% of maximum isometric voluntary contraction after 4 hours of lifting. RESULTS: There were no significant differences in maximum isokinetic endurance, or in the slope of median frequency, between lifting with a back belt and lifting without a back belt. Similarly, a modified Borg scale and a postexperiment survey question were unable to distinguish between wearing a back belt and not wearing a back belt. CONCLUSION: There were no significant differences in maximum isokinetic endurance and electromyographic spectral parameters of the back extensor muscles as a result of wearing a back belt during heavy lifting and lowering tasks.

Clinical and functional outcomes of internal fixation with intertrochanteric antegrade nail in older patients with proximal extracapsular femoral fractures.

PURPOSE: The intertrochanteric Trigen Intertan(®) nail (Smith & Nephew, Memphis, TN) is a popular fixation device for proximal extracapsular femoral fractures (PEFFs). We evaluated clinical and functional outcomes in patients with PEFFs treated with Trigen Intertan(®) nail. METHODS: In a single-site, prospective observational study, clinical and functional parameters were recorded for all patients admitted to the Emergency Department with PEFFs from June 2008 through June 2011. Patients with severe cognitive impairment, severe disability, neoplastic pathological fractures, or suffering from terminal illnesses were not eligible for the study. Fractures were classified according to the AO/OTA classification system. Preoperative physical fitness was assessed via the American Association of Anaesthetists (ASA) score. The Barthel index was used to quantify the level of physical function before fracture and at follow-up. RESULTS: One-hundred thirty-five patients with PEFFs were eligible for inclusion during the 3-year survey (mean age 83.2 ± 9.5 years; 82 % females). Fracture type distribution was as follows: A1.1 = 18 %, A1.2 = 7 %, A1.3 = 5 %, A2.1 = 44 %, A2.2 = 21 %, A2.3 = 5 %. All patients were treated with Trigen Intertan(®) nail. Two patients experienced a fracture of the femoral shaft during the insertion of a long nail for an A2.3 fracture. Weight-bearing was allowed between the third and tenth postoperative day depending on pain tolerance and general conditions. No loss of reduction, collapse of the femoral neck, nonunion or fixation failure were observed. Two patients died within 10 days postoperatively, and nine within 6 months after surgery. Functional status 1 month after surgery was lower than pre-fractural levels, and improved over follow-up. At 6 months, functional status was comparable to the pre-fractural level. CONCLUSIONS: Trigen Intertan(®) produces highly satisfactory clinical and functional results in older patients with PEFFs. Complete functional recovery is obtained on average 6 months after surgery.

Investigation of the PGNAA using the LaBr3 scintillation detector.

The Joint Research Centre of the European Commission develops instrumentation for detection of hazardous materials. In relation to this a new experimental facility was constructed for research into methods applying the detection of characteristic gamma rays subsequent to neutron irradiation. This includes the detection of prompt gamma rays from neutron inelastic scattering and neutron capture. For this purpose the device employs LaBr(3) scintillation detectors. The paper investigates the applicability of the LaBr(3) scintillation detector to PGNAA.

The design of manual handling tasks: revised tables of maximum acceptable weights and forces.

Four new manual handling experiments are reviewed. The experiment used male and female subjects to study lifting, lowering, pushing, pulling, and carrying tasks. Each experiment used a psychophysical methodology with measurements of oxygen consumption, heart rate, and anthropometric characteristics. Independent variables included task frequency, distance, height and duration; object size and handles; extended horizontal reach; and combination tasks. The results of the four experiments were integrated with the results of seven similar experiments published previously by this laboratory. The integrated data were used to revise maximum acceptable weights and forces originally published in 1978. The revised tables are presented and compared with the original tables.

The prediction of WBGT from the Botsball.

This study investigated the relationship between the Botsball (BB) and WBGT in varied environmental conditions. Two levels of radiant heat, two levels of air movement, three levels of relative humidity, and dry bulb temperatures ranging between 17.2 and 42.8 degrees C (63 and 109 degrees F) yielded 210 different environmental conditions. The results indicate that if good estimates of wind speed, humidity and radiant heat are available, BB can predict WBGT with +/-0.4 degrees C (90% confidence level). Only when there is limited knowledge of the type of environment does the predictability fall to +/-2.9 degrees C (90% confidence level).

Further studies of psychophysically determined maximum acceptable weights and forces.

The effects of lifting boxes without handles, pulling long distances, carrying different size boxes, combining three handling tasks, and lifting with extended horizontal reach were studied using a psychophysical methodology. Six male industrial workers performed 42 variations of lifting, lowering, pushing, pulling, and carrying tasks. Lifting boxes without handles produced consistent decreases (median, 16%) in maximum acceptable weights when compared with lifting boxes with handles. Lifting with extended horizontal reach (approximately 48 cm) produced consistent decreases (median, 48%) in maximum acceptable weights when compared with lifting close to the body (approximately 17 cm). No significant heart rate or oxygen consumption differences occurred in either of these variables. No significant differences in maximum acceptable weight of carry were observed among box sizes; however, the maximum acceptable force of pulling was lower for longer (15.2 m) pulling tasks. The maximum acceptable weight for combination tasks was similar to that of the limiting component.

Psychophysical study of six hand movements.

This study represents a continuation of a series of psychophysical studies on repetitive motions of the wrist and hand conducted at the Liberty Mutual Research Center for Safety and Health. The purpose of the study was to quantify maximum acceptable forces of six motions performed on separate days but within the context of the same experiment. The six motions were wrist flexion with a power grip, wrist extension with a power grip, wrist flexion with a pinch grip, wrist extension with a pinch grip, ulnar deviation with a power grip, and a handgrip task (with a power grip). A psychophysical methodology was used in which the subject adjusted the resistance on the handle and the experimenter manipulated or controlled all other variables. Thirty-one subjects performed the six tasks at repetition rates of 15, 20 and 25 motions/min. Subjects performed the tasks for 7 h per day, 5 days per week, for 4 weeks. The subjects were instructed to work as if they were on an incentive basis, getting paid for the amount of work performed. Symptoms were recorded by the subjects during the last 5 min of each hour. The results revealed that maximum acceptable torques ranged from 11 to 19% of maximum isometric torque depending on frequency and motion. Maximum acceptable torques for the tasks that could be compared with previous studies showed the same patterns of response. However, the selected forces were substantially lower using the mixed protocol. A table of maximum acceptable torques and forces is presented for application in the field.

The effects of task duration on psychophysically-determined maximum acceptable weights and forces.

The purpose of this experiment was to investigate maximum acceptable weights and forces when performing manual handling tasks continuously for four hours at frequencies of 4.3 min-1 or slower. Twelve female and ten male second shift industrial workers performed 18 varieties of lifting, lowering, pushing, pulling, and carrying. A psychophysical methodology was employed, whereby the subjects were asked to select a workload they could sustain for 8 h 'without straining themselves or without becoming unusually tired, weakened, overheated or out of breath'. Measurements of heart rate, oxygen consumption, dynamic and static strengths were also taken. The weights selected after 40 min were not significantly different from the weights selected after four hours. The average oxygen consumption for the fast tasks was 28% VO2 max, within physiological guidelines for eight hours. The results also revealed that the maximum acceptable weights for the combination task of lifting, carrying, and lowering were limited by the lifting and lowering components. It is concluded from the results of this study that the psychophysical methodology is appropriate for determining maximum acceptable weights for task frequencies of 4.3 min-1 or slower. It is also concluded that the maximum acceptable weight for a combination task is limited by the lowest acceptable weight of any of the components.

Psychophysical studies of repetitive wrist flexion and extension.

The purpose of this experiment was to investigate the feasibility of using psychophysical methods to determine maximum acceptable forces for various types and frequencies of repetitive wrist motion. Four adjustable work stations were built to simulate repetitive wrist flexion with a power grip, wrist flexion with a pinch grip, and wrist extension with a power grip. The study consisted of two separate experiments. Subjects worked for two days per week during the first experiment, and five days per week during the second experiment. Fifteen women completed the first experiment, working seven hours each day, two days per week, for 20 days. Repetition rates of 2, 5, 10, 15 and 20 motions per minute were used with each flexion and extension task. Maximum acceptable torques were determined for the various motions, grips, and repetition rates without dramatic changes in wrist strength, tactile sensitivity, or number of symptoms. Fourteen different women completed the second experiment, performing a wrist flexion motion (power grip) fifteen times per minute, seven hours per day, five days per week, for 23 days. There were no significant differences in maximum acceptable torque from day to day. However, the average maximum acceptable torque for a five days per week exposure was 36.3% lower than for the same task performed two days per week. Assuming that maximum acceptable torques decrease 36.3% for other repetition rates and motions, tables of maximum acceptable force were developed for female wrist flexion (power grip), female wrist flexion (pinch grip), and female wrist extension (power grip).

Maximum acceptable forces for repetitive ulnar deviation of the wrist.

The purpose of this experiment was to quantify maximum acceptable forces for ulnar deviation motions of the wrist at various repetition rates. Subjects grasped a handle with a power grip and moved it through a 1.40 rad (80 degrees) ulnar deviation wrist motion (similar to a knife cutting task). A psychophysical methodology was used in which the subject adjusted the resistance on the handle and the experiment manipulated or controlled all other variables. Two series of experiments were conducted. Thirteen subjects completed the first series, which investigated repetition rates of 15 and 20 motions per minute. Eleven subjects completed the second series, which investigated 15, 20, and 25 motions per minute. Subjects performed for 7 hours per day, 5 days per week, for 4 weeks in the first series and 5 weeks in the second series. The subjects were instructed to work as if they were on an incentive basis, getting paid for the amount of work they performed. Symptoms were recorded by the subjects during the last 5 minutes of each hour. The results are presented and compared with maximum acceptable forces for wrist flexion and extension.

Maximum acceptable forces of dynamic pushing: comparison of two techniques.

The purpose of this experiment was to investigate maximum acceptable initial and sustained forces while performing a push of 7.6 m, performed at a frequency of 1 push min-1 on a magnetic particle brake treadmill and a high-inertia push-cart. Eight male industrial workers performed a 40 min treadmill pushing task in the context of a larger experiment and two, 2 h push-cart tasks with a unique water loading system. A psychophysical methodology was employed, whereby the subjects were asked to select a workload they could sustain for 8 h without straining themselves or without becoming unusually tired, weakened, overheated or out of breath. The results revealed that maximum acceptable initial and sustained forces of pushing on the high inertia cart were significantly higher (28 and 23%, respectively) than pushing forces on the magnetic particle brake treadmill. It was concluded that adjustments to the pushing and pulling data bank by Snook and Ciriello (1991) may be appropriate if verification of this experiment yields similar results.