Cross-cultural adaptation and validation of a Spanish version of the self-administered foot evaluation questionnaire (SAFE-Q).

BACKGROUND: The self-administered foot evaluation questionnaire is a comprehensive measure for assessing the perception of patients regarding their foot-related problems. However, it is currently only available in English and Japanesse. Therefore, this study aimed to cross-culturally adapt the questionnaire to Spanish and assess its psychometric properties. METHODS: The methodology recommended by the International Society for Pharmaco Economics and Outcomes Research for translating and validating patient-reported outcome measures was followed for the Spanish translation. After a pilot study with 10 patients and 10 controls, an observational study was carried out between March and December 2021. The Spanish version of the questionnaire was filled by 100 patients with unilateral foot disorders, and the time spent to complete each questionnaire was recorded. Cronbach's alpha was calculated to analyze the internal consistency of the scale and Pearson's correlation coefficients for the degree of inter-subscale associations. RESULTS: The maximum correlation coefficient for the Physical Functioning, Daily Living, and Social Functioning subscales was 0.768. The inter-subscale correlation coefficients were significant (p < 0.001). Additionally, the value of Cronbach's alpha for the whole scale was 0.894 (95% confidence interval, 0.858-0.924). The values of Cronbach's alpha varied between 0.863 and 0.889 when the value of one of the five subscales was suppressed, which can be considered a measure of good internal consistency. CONCLUSION: The Spanish version of the questionnaire is valid and reliable. The method followed for its transcultural adaptation ensured its conceptual equivalence with the original questionnaire. Health practitioners can use the self-administered foot evaluation questionnaire as a complementary method to assess the interventions performed for ankle and foot disorders among native Spanish speakers; however, further research is necessary to assess its consistency for use by populations from other Spanish-speaking countries.

Does thread shape affect the fixation strength of the bioabsorbable interference screws for anterior cruciate ligament reconstructions? A biomechanical study.

BACKGROUND: The purpose of this study was to compare the biomechanical behaviour of two bioabsorbable interference screws with different geometries. METHODS: Two different pitch (2.5 and 5 mm) bioabsorbable interference screws, both 9 × 30 mm, were tested. Tests were performed with forty bovine digital extensor tendons and skeletally mature porcine tibiae. Two protocols of cyclic tests at 1 Hz were performed: 1000 cycles from 50 to 250 N, and 5000 cycles from 100 to 300 N (n = 10 for each type of test and screw). After the cyclic loading, a final ramp displacement until failure at 0.5 mm/s was applied. RESULTS: The stiffness after the cyclic phase of the tests was not statistically different between the two screws (1000th cycle: 2.5 mm pitch 280.3 ± 56.4 N/mm, 5 mm pitch 275.2 ± 65.0 N/mm, P = .965; 5000th cycle: 2.5 mm pitch 281.3 ± 66.4 N/mm, 5 mm pitch 286.1 ± 79.4 N/mm, P = .814). The yield load was not significantly different between the screws (1000 cycle tests: 2.5 mm pitch 482.2 ± 120.2 N, 5 mm pitch 495.9 ± 131.3 N, P = .508; 5000 cycle tests: 2.5 mm pitch 476.4 ± 65.3 N, 5 mm pitch 494.3 ± 39.2 N, P = .391). No correlation was found between the insertion torque and yield load (1000 cycle tests, R2 = 0.013; 5000 cycle tests, R2 = 0.006). CONCLUSIONS: The pitch of bioabsorbable interference screws does not seem to affect fixation strength. Also, the authors recommend not to use insertion torque alone to estimate the fixation strength.

Clinical effectiveness and safety of Weil's osteotomy and distal metatarsal mini-invasive osteotomy (DMMO) in the treatment of metatarsalgia: A systematic review.

BACKGROUND: Weil's osteotomy (WO) is the most applied surgical treatment for metatarsalgia, a persistent pain in the lesser metatarsals' heads. We aim to review its effectiveness and safety compared to the percutaneous technique known as distal metatarsal mini-invasive osteotomy (DMMO). METHODS: Systematic review in Medline, Pubmed, Embase, Cinahl and Cochrane Library. We included studies that directly compared WO and DMMO for the treatment of primary metatarsalgia. Data on pain, function, complications and patients' satisfaction were extracted and narratively synthesized. RESULTS: Four retrospective studies were identified. There were no significant differences in clinical effectiveness or patients' satisfaction. Time to bone healing was significantly longer for DMMO, whereas WO showed more wound problems and metatarsophalangeal stiffness. Other complications were infrequent in the two procedures. CONCLUSION: Evidence on the direct comparison of WO and DMMO is scarce and of low quality. Randomized studies are needed in order to control for potential confounders.

Use of screw locking elements improves radiological and biomechanical results of femoral osteotomies.

BACKGROUND: Dynamic compression plate (DCP) constructs provide inadequate fixation in cases of poor bone quality and early weight-bearing. Screw locking elements (SLE) are flat locking nuts placed at the end of the screw to prevent screw stripping from the bone, improving fixation stability. The purpose of this work was to compare biomechanical and radiological evaluations of femoral ovine osteotomies fixed using DCP constructs with and without SLE. METHOD: A dyaphyseal femoral osteotomy was performed in sixteen adult sheep and fixed with a DCP and cortical screws. Half of the animals were operated on with a SLE on each side of the osteotomy and the rest without the addition of SLE. Four animals of each group were euthanized after 8 weeks, and the remaining after 16 weeks. Both femora of each animal were radiographed and mechanically tested in torsion. RESULTS: Radiologically femoral malalignment or screw loosening was observed in six out of the eight animals operated on without SLE. In contrast, all animals subjected to the operation with SLE showed complete radiological consolidation of the osteotomy. Seven of these eight animals showed normal femoral alignment and no osteosynthesis failure. Stiffness of the bones fixed with SLE was among 145% and 177% the value of their contralateral non-operated femurs (all animals of this group showed greater stiffness on the operated bone than its contralateral non-operated femur). However, stiffness of the bones operated on without SLE was among 58% and 87% the value of the stiffness of their contralateral non-operated bone (all animals of this group showed greater stiffness on the non-operated bone than the osteotomized ones). CONCLUSIONS: Use of SLE avoided loosening of the system and stimulated stronger osteotomy consolidation. Clinical application of this improved system may thus be a feasible and cost-effective alternative to other more rigid and expensive bone fixation techniques.

Temporal Changes in Clinical Outcomes after Minimally Invasive Surgery for Hallux Valgus Correction in Women without Postoperative Complications.

Minimally invasive surgery (MIS) is currently used to correct hallux valgus deformities. Most studies reporting on MIS techniques to correct hallux valgus deformities included patients with postoperative complications. These reported complications, with an average rate of 23%, had significant negative effects on the clinical outcomes in this patient population. In the present study, a cohort of 63 women who underwent MIS hallux valgus correction was assessed preoperatively and at a mean follow-up of 1.0, 4.7, and 6.5 years using the American Orthopaedic Foot and Ankle Society (AOFAS) scale and the Manchester Oxford Foot Questionnaire (MOXFQ). The main criterion for inclusion in this cohort was a lack of complications during the entire follow-up period. The results showed significant improvements in both AOFAS and MOXFQ scores between the preoperative and 1-year follow-up assessments. By contrast, clinically small and nonsignificant changes were observed among postoperative follow-up values. The number of enrolled patients needs to be increased in future studies, with different surgeons and techniques included. Nevertheless, our study findings will inform patients about the outcomes they can expect over the years if no complications occur.

Pre- and Post-Operative Relationship between Radiological Measures and Clinical Outcomes in Women with Hallux Valgus.

The surgical correction of a hallux valgus (HV) deformity improves radiological parameters and clinical outcomes. However, it is not known how these improvements are related between themselves. In this retrospective study, 73 women were assessed preoperatively and 60 months after HV surgical correction. Several radiological parameters were measured: the hallux valgus angle (HVA), I−II intermetatarsal angle (IMA) and sesamoid position. The functional outcomes were assessed using the American Orthopaedic Foot and Ankle Society (AOFAS) Hallux Metatarsophalangeal-Interphalangeal (HMI) scale, and patient-reported outcomes (PROMs) were recorded with the Manchester−Oxford Foot Questionnaire (MOXFQ). A pre−post-surgery comparison of radiological and clinical values was performed, the correlation among them was studied and the differences pre−post-surgery in the radiological measurements compared with those for the clinical outcomes were studied. The results show that all the radiological parameters, functional outcomes and PROMs improved significantly from their pre-operative values to the follow-up values. Multivariate regression analysis showed a significant relationship (p < 0.001) between the differential pre−post-surgery AOFAS scoring only with two sesamoid position differential pre−post-surgery measures: position of medial sesamoid (PMS) and translation of the first metatarsal head (TMH). However, no significant association was observed between the pre−post-surgery radiological differences and the pre−post-surgery MOXFQ scoring.

Isometric Knee Muscle Strength and Patient-Reported Measures Five Years after Anterior Cruciate Ligament Reconstruction: Comparison of Single versus Dual Autograft Hamstring Tendon Harvesting.

There is some controversy regarding the use of one or two hamstring tendons for anterior cruciate ligament reconstruction (ACLR). In this study, two cohorts of 22 male patients underwent an ACLR with hamstring tendon autografts. One cohort was reconstructed through an all-inside technique with the semitendinosus tendon (ST group) and the other with the semitendinosus and gracilis tendons (ST-G group). Anterior tibial translation (ATT), Lysholm, and IKDC scores were assessed preoperatively and five years postoperation. Additionally, isometric knee muscle strength was manually measured in both groups and in another cohort of 22 uninjured control male subjects five years after the operation. There were no significant differences in ATT and Lysholm scores between the operated groups. The IKDC score was lower in the ST-G group than in the ST group­9.57 (CI 14.89−4.25) (p < 0.001). No significant differences between injured and uninjured knees were detected in hamstring to quadriceps ratio strength and quadriceps limb symmetry index of the two operated groups, but the hamstring limb symmetry index was significantly lower in the ST-G group than in the ST and control groups. This study shows that using an ST-G autograft for ACLR yielded less flexor strength and worse results in some patient-reported outcome measures (PROM) than using an ST autograft five years after the operation. The observed results let us suggest that the use of one autograft hamstring tendon for ACLR is clinically preferable to the use of two hamstring tendons.

Correlation among Knee Muscle Strength and Self-Reported Outcomes Score, Anterior Tibial Displacement, and Time Post-Injury in Non-Coper Anterior Cruciate Ligament Deficient Patients: A Cross-Sectional Study.

Little attention has been paid to knee muscle strength after ACL rupture and its effect on prognostic outcomes and treatment decisions. We studied hamstrings (H) and quadriceps (Q) strength correlation with a patient-reported outcome measures score (International Knee Documentation Committee, IKDC), anterior tibial translation (ATT), and time post-injury in 194 anterior cruciate ligament deficient patients (ACLD) who required surgery after a failed rehabilitation program (non-copers). The correlation between knee muscle strength and ATT was also studied in 53 non-injured controls. ACLD patients showed decreased knee muscle strength of both the injured and non-injured limbs. The median (interquartile range) values of the H/Q ratio were 0.61 (0.52-0.81) for patients' injured side and 0.65 (0.57-0.8) for the non-injured side (p = 0.010). The median H/Q ratio for the controls was 0.52 (0.45-0.66) on both knees (p < 0.001, compared with the non-injured side of patients). The H/Q, ATT, and time post-injury were not significantly correlated with the IKDC score. ATT was significantly correlated with the H/Q of the injured and non-injured knees of patients, but not in the knees of the controls. Quadriceps strength and H/Q ratio were significantly correlated with ATT for both limbs of the patients. IKDC score correlated significantly with the quadriceps and hamstrings strengths of the injured limb but not with the H/Q ratio, ATT or time passed after injury.

In Vitro Testing of 2 Adjustable-Loop Cortical Suspensory Fixation Systems Versus Interference Screw for Anterior Cruciate Ligament Reconstruction.

BACKGROUND: It is not clear whether the mechanical strength of adjustable-loop suspension devices (ALDs) in anterior cruciate ligament (ACL) reconstruction is device dependent and if these constructs are different from those of an interference screw. PURPOSE: To compare the biomechanical differences of 2 types of ALDs versus an interference screw. STUDY DESIGN: Controlled laboratory study. METHODS: ACL reconstruction was performed on porcine femurs and bovine extensor tendons with 3 types of fixation devices: interference screw, UltraButton (UB) ALD, and TightRope (TR) ALD (n = 10 for each). In addition to specimen testing, isolated testing of the 2 ALDs was performed. The loading protocol consisted of 3 stages: preload (static 150 N load for 5 minutes), cyclic load (50-250 N at 1 Hz for 1000 cycles), and load to failure (crosshead speed 50 mm/min). Displacement at different cycles, ultimate failure load, yield load, stiffness, and failure mode were recorded. RESULTS: In specimen testing, displacement of the ALDs at the 1000th cycle was similar (3.42 ± 1.34 mm for TR and 3.39 ± 0.92 mm for UB), but both were significantly lower than that of the interference screw (7.54 ± 3.18 mm) (P < .001 for both). The yield load of the UB (547 ± 173 N) was higher than that of the TR (420 ± 72 N) (P = .033) or the interference screw (386 ± 51 N; P = .013), with no significant difference between the latter 2. In isolated device testing, the ultimate failure load of the TR (862 ± 64 N) was significantly lower than that of the UB (1879 ± 126 N) (P < .001). CONCLUSION: Both ALDs showed significantly less displacement in cyclic loading at ultimate failure than the interference screw. The yield load of the UB was significantly higher than that of the other 2. The ultimate failure occurred at a significantly higher load for UB than it did for TR in isolated device testing. CLINICAL RELEVANCE: Both UB and TR provided stronger fixation than an interference screw. Although difficult to assess, intrinsic differences in the mechanical properties of these ALDs may affect clinical outcomes.

Anterior tibial translation and patient-reported outcomes after anterior cruciate ligament reconstruction with a tape locking screw: A 5-year follow-up study.

BACKGROUND: The Tape Locking Screw system (TLS) is a recognised technique used in anterior cruciate ligament reconstruction (ACLR). However, only a few previous studies have reported associated outcomes, all of which had been examined over a short-term period. The aim of this study was to assess the time-dependent changes in the objective and patient-reported outcome measures (PROM) in a group of patients with anterior cruciate ligament deficiency who have been operated on with this technique. HYPOTHESIS: Previously reported satisfactory short-term outcomes following TLS persist for several years after the operation. PATIENTS AND METHODS: This study was a retrospective observational study including 26 patients, who were followed after unilateral ACLR with TLS. Anterior tibial translation (ATT) was measured in both knees using the KT-1000 arthrometer and two PROMs: International Knee Documentation Committee (IKDC) and Lysholm subjective form scores were examined preoperatively, 6 months postoperatively, and annually for 5 years thereafter in all patients. RESULTS: One patient suffered a rupture of the graft, and one patient had a screw loosening. Two patients were lost for follow-up, so 22 patients were the final study group. Median (25-75%) ATT side-to-side differences between the injured and uninjured sides were 4 (3,5-4)mm preoperatively, 0,75 (0-1)mm 1 year postoperatively, and 0,75 (0-1)mm 5 years after the operation (P<0.001). Median (25-75%) IKDC scores were 44.25 (35.6-55.15), 92.55 (87.08-96.6), and 95.4 (90.8-97.7) points preoperatively and 1 year (P<0.001) and 5 years postoperatively, respectively. Median (25-75%) Lysholm scores were 52 (38.75-64.5), 95.5 (94.75-99.25), and 97.5 (95-99) points preoperatively and 1 year (P<0.001) and 5 years postoperatively, respectively. DISCUSSION: ACLR with TLS might already achieve favourable outcomes 1 year postoperatively, when measured objectively (ATT) and with PROMs. These outcomes persist 5 year postoperatively. LEVEL OF EVIDENCE IV: retrospective cohort study.

A randomized controlled trial of dorsal web space versus palmar midline injection of steroid in the treatment of trigger digits.

One hundred and sixty patients were enrolled in a prospective randomized controlled trial to assess whether a steroid injection through the dorsal web space was less painful than the palmar midline technique in the treatment of trigger digits and whether they were equally effective. There were 116 women and 44 men with a mean age of 60 years. The mean visual analogue score for pain during the injection was 3.6 in the dorsal web space group and 5.4 in the palmar midline group on a scale of 0-10. The overall success of treatment in the dorsal group was 67%, whereas it was 56% in the palmar group. No complications were noted. We concluded from this study that the dorsal web space technique is less painful and at least as effective as the palmar midline technique.Level of evidence: I.

Maintaining High Strength in Mg-LPSO Alloys with Low Yttrium Content Using Severe Plastic Deformation.

Alternative processing routes such as powder metallurgy, the extrusion of recycled chips, or equal channel angular pressing (ECAP) have been considered for effective methods of maintaining the high mechanical strength of Mg-Y-Zn alloys containing long-period stacking ordered structures with respect to the alloy processed by the conventional extrusion of as-cast ingots with the advantage of minimizing the yttrium content. A yield stress similar to that found for extruded Mg97Y2Zn1 alloy can be attained with only half of the usual yttrium and zinc additions thanks to the grain refinement induced by ECAP processing. The properties of Mg98.5Y1Zn0.5 subjected to ECAP are maintained up to 200 °C, but superplastic behavior is found above this temperature when the alloy is processed through a powder metallurgy route.

Influence of the number and position of stripped screws on plate-screw construct biomechanical properties.

INTRODUCTION: Screw stripping is a common situation in fracture fixation, particularly in osteopenic bone treatment. Surgeons' perception of screw stripping is relatively poor and the real number of loose screws in every plate-screw construct is unknown. The biomechanical and clinical implications of the different possible screw-stripping situations are also unidentified. In this study, construct stiffness in different scenarios of stripped screws is investigated. METHOD: A bone surrogate comminuted osteoporotic fracture was fixed with four screws in both sides of the fracture gap in 75 specimens. In four groups, one or two screws closest or distal to the gap were over-tightened and left in place in one part of the construct and the remaining screws were tightened with 0.3N m torque (four groups). In the fifth group (control), all the screws were tightened with 0.3N m torque. Construct stiffness was tested in terms of compression, bending, and torsion for 1000 cycles. RESULTS: When one or two screws closest to the gap were stripped, stiffness only decreased by, respectively, 5.7% or 7.6% under compression and 4.7% or 6.7% under bending; however, stiffness in torsion was 15.1% or 32%, respectively, lower than the initial stiffness. When a screw distal to the gap was stripped, the stiffness decreased by 28% under bending and 10% under compression; no change was noted under torsion. When two screws distal to the gap were stripped, the stiffness decreased by 11% in compression, collapsed under bending, and decreased by 8% under torsion. CONCLUSIONS: Position and number of stripped screws affect the biomechanical properties of a construct in different ways, depending on the acting forces.

Locking versus non-locking one-third tubular plates for treating osteoporotic distal fibula fractures: a comparative study.

INTRODUCTION: Ankle fractures represent the third most common fracture in elderly patients, after hip and wrist fractures. Distal fibula fractures in this population are closely related to osteoporosis, which renders commonly used methods of internal fixation technically demanding and prone to failure. Currently there is a tendency to fix osteoporotic metaphyseal and epiphyseal fractures with locking plates. However, published accounts about the use of this technology in osteoporotic distal fibula fractures are scarce. In this study we compare the results of two groups of patients who underwent surgery for these types of fracture, one group received locking and the other non-locking screws, both using one-third tubular plates. METHODS: Sixty-two patients, aged over 64 years, underwent surgery for osteoporotic distal fibula fractures between 2011 and 2014. Forty-five of them were stabilized with a non-locking plate and the remaining 17 with a locking plate fixation. Follow-up was performed at 4, 8, 12, 26, and 52 weeks. Results were assessed according to the AOFAS Ankle-Hindfoot Score and radiological criteria for consolidation. RESULTS: Average time to union and AOFAS scores at 6 and 12 months were similar in both groups, including for the individual categories: function, pain, mobility, and alignment. Only time until partial weight bearing was significantly lower in the locking plate group (4.69 ± 2.63 vs 7.77 ± 4.30, p = 0.03). The most common complications were wound dehiscence and superficial infection (two cases of both). CONCLUSIONS: Both locking and conventional non-locking plates achieved similar treatment outcomes in this group of osteoporotic patients aged over 64. However, locking plates may offer more benefits in cases that have to take into account immobilization time and concomitant soft-tissue damage.

Can an expansion device be used in anterior cruciate ligament reconstruction? An in vitro study of soft tissue graft tibial fixation.

BACKGROUND: The purpose of this study was to compare the mechanical properties of an interference screw with an expansion device in anterior cruciate ligament (ACL) reconstruction. METHODS: A total of 52 porcine tibia and 20 polyurethane foam blocks (0.16g/cm3) were used. Forty pullout tests were carried out to combine the two types of bones - surrogate and porcine - with the two fixation systems: interference screw and expansion device (n=10 per group). Thirty-two cyclic tests (n=8 per group) were carried out with both fixation devices in porcine bone at two different force amplitudes (100N and 200N). RESULTS: Stiffness and load values (mean±SD) at six millimeters of displacement for the expansion device and the interference screw were 74±33N/mm, 318±135N, and 52±28N/mm, 205±70N, respectively, showing a difference in stiffness (P=0.016) and load at six millimeters of displacement (P=0.001). No correlation between insertion torque and the ultimate failure load was found for both fixation devices tested. In cyclic tests, significantly higher (P<0.001) numbers of cycles (mean±SD) were reached with the expansion device (81,014±30,291 at 100N; 13,462±11,351 at 200N) than with the interference screw (15,100±8623 at 100N; 343±113 at 200N) at six millimeters of displacement. CONCLUSION: The use of an expansion device for ACL reconstructions seemed to be a promising alternative to an interference screw. Insertion torque alone was not a useful predictor of graft fixation strength in ACL reconstructions.

Properties of WZ21 (%wt) alloy processed by a powder metallurgy route.

Microstructure, mechanical properties and corrosion behaviour of WZ21 (%wt) alloy prepared by a powder metallurgy route from rapidly solidified powders have been studied. Results were compared to those of the same alloy prepared through a conventional route of casting and extrusion. The microstructure of the extruded ingot consisted of α-Mg grains and Mg3Zn3Y2 (W-phase) and LPSO-phase particles located at grain boundaries. Moreover, stacking faults were also observed within α-Mg grains. The alloy processed by the powder metallurgy route exhibited a more homogeneous and finer microstructure, with a grain size of 2 µm. In this case W-phase and Mg24Y5 phase were identified, but not the LPSO-phase. The microstructural refinement induced by the use of rapidly solidified powders strengthened the alloy at room temperature and promoted superplasticity at higher strain rates. Corrosion behaviour in PBS medium evidenced certain physical barrier effect of the almost continuous arrangements of second phases aligned along the extrusion direction in conventionally processed WZ21 alloy, with a stable tendency around 7 mm/year. On the other hand, powder metallurgy processing promoted significant pitting corrosion, inducing accelerated corrosion rate during prolonged immersion times.

Normative database of isometric cervical strength in a healthy population.

OBJECTIVES: This was a descriptive study involving maximal and average isometric strength measurements of the cervical musculature. The purpose of this study was 1) to determine the test-retest reliability of a computerized dynamometer for measuring muscular strength of the neck flexor and extensor muscles in a healthy population, and 2) to afford a normative database of the maximal and averaged isometric strength of the cervical flexors and extensors in a healthy population of 94 volunteers. The literature contains only a few descriptive studies pertaining to strength levels of the cervical musculature; none of these studies used a computerized dynamometer to determine cervical isometric strength. Only a few studies include cervical flexor and extensor isometric strength, evaluating its normal ratio as well as their correlation to body mass index. METHODS: Testing was carried out using a computerized dynamometer to measure isometric cervical strength at 0 degrees (neutral), 5 degrees, and 10 degrees of flexion and extension of the neck. RESULTS: Men show approximately 30 to 40% more strength than women both for flexion and extension at all angles and age groups. Neutral positioning showed the maximum strength values for both flexion and extension. CONCLUSION: There was a significant negative correlation between age and cervical strength and a significant positive correlation between weight and strength and between height and strength. However, the flexor/extensor ratio was maintained around 0.6 in all ages.

Influence of the crosshead rate on the mechanical properties of fixation systems of ACL tendon grafts.

Anterior cruciate ligament (ACL) reconstruction is one of the most important aspects of knee surgery. For this purpose, several fixation devices have been developed, although the interference screw is the most frequently used. The most typical biomechanical test of these devices consists of placing them in a testing machine and subjecting them to a pull-out test. However, insufficient attention has been paid to the influence of the displacement test rate on the mechanical properties of the fixation system. The aim of this study is to compare the influence of the crosshead rate in the biomechanical test of two different devices for the fixation of ACL tendon grafts. One hundred in vitro tests were performed using porcine tibiae and bovine tendons. The fixation devices used were (1) an interference screw and (2) a new expansion device. All ACL reconstructions were subjected to pull-out test to failure. Five crosshead rates were employed in a range from 30 mm/min to 4000 mm/min. Statistical analyses of the results show that, for the two devices, the rate has a significant effect on both maximum force and stiffness. Moreover, the new expansion device showed lesser dependency on the crosshead rate than the interference screw.

History of arthroscopy.

Arthroscopy has developed as one of the branches of former cystoscopy. During the past 200 years a few people have made invaluable contributions to development of arthroscopy (Bozzini, Takagi, Watanabe...) After the World War II scientific and technological progress was so fast that arthroscopy proved to be a valuable tool in orthopedics, not only as a diagnostic, but also as a therapeutic procedure.