Apoptosis of tubular epithelial cells in familial juvenile gouty nephropathy

Chronic ruptures of the patellar tendon are uncommon injuries. They are technically difficult to repair because of scar formation, poor quality of the remaining tendon, and quadriceps muscle atrophy and contracture. We report the reconstruction of a chronic patellar tendon rupture with an interesting complication, a tibial stress fracture. The reconstruction was performed 3 months after the injury using an Achilles tendon-bone allograft and reinforcing suprapatellar wire. At 2 weeks postoperatively, the patient had attained full extension and 90 degrees of flexion. Ten months after the index procedure, the patient had range of motion 0 degrees to 120 degrees and was diagnosed with a healing tibial stress fracture. At 17 months postoperatively, the patient had attained full extension, 120 degrees of flexion, and 85% quadriceps strength. The preoperative goals of attaining full range of motion, improving quadriceps strength, obtaining anatomic patellar alignment, and restoring function were obtained despite the complication of a tibial stress fracture. Although this reconstructive procedure is technically demanding, with potential complications, the functional results obtained can be excellent.     

Anterior cruciate ligament reconstruction with the patellar tendon augmented by absorbable artificial materials. A histological and molecular biological study in rabbits

An experimental study was performed to investigate the histological and molecular biological properties of reconstructed anterior cruciate ligaments (ACL) using the patellar tendon augmented by absorbable artificial material in rabbits. Thirty rabbits underwent ACL reconstruction with the patellar tendon (non-augmented group), and 30 with the patellar tendon augmented by a polyglactin 910 mesh (augmented group). They were respectively sacrificed at at 1, 2, 3, 4, 6, 8 and 12 weeks after surgery for histological and molecular biological examination. Histologically, the fibrocytes were disappeared in deep portion of transplanted graft at 2 weeks after surgery in both groups. The graft was replaced with granulated tissues at 6 weeks in the augmented group, but it took 8 weeks in the non-augmented group. At 12 weeks, the graft showed hypocellularity with regularly oriented fibers in the augmented group, while it still showed hypercellularity with disoriented fibers in the non-augmented group. Molecular biologically, after the reconstruction at one week, the relative radioactivity in the graft was 1.05 in the non-augmented group, and 2.10 in the augmented group. Additionally the level of the alpha 2 (I) collagen mRNA was also significantly higher in the augmented group than that in the non-augmented group. These results suggested that a polyglactin 910 mesh had an effect on the process of reorganization and remodeling in the transplanted patellar tendon during the post-operative period in rabbit.     

Quadriceps atrophy after partial resection of the patellar tendon: an experimental study in a rat model

Quadriceps muscle atrophy of rats was examined after resection of the central third (group 1) or the lateral two thirds (group 2) of the patellar tendon, the tensor fascia lata (group 3), or the medial hamstring (group 4). The quadriceps atrophied in groups 1 and 2, and more so in group 2, but there was no atrophy in groups 3 or 4. Thus, after an anterior cruciate ligament reconstruction procedure using the patellar tendon, resection of the patellar tendon itself leads to quadriceps atrophy and the extent of atrophy is related to the resected width.     

Homoeopathy for delayed onset muscle soreness: a randomised double blind placebo controlled trial

This report describes a technique for the reconstruction of a patellar tendon-tibial tubercle deficiency. This technique uses an easy-to-harvest, low-morbidity graft (autogenous quadriceps tendon), while allowing aggressive rehabilitation as a result of the strength of the graft.     

The outcome of operatively treated anterior cruciate ligament disruptions in the skeletally immature child

The purpose of this study was to evaluate the outcome of transphyseal ligament reconstruction in skeletally immature children with midsubstance anterior cruciate ligament (ACL) disruption. Five consecutive patients (mean age, 12.9 years; range, 8 to 14 years) with radiographically documented "wide" open growth plates and a minimum of 5 cm of expected remaining growth, underwent intra-articular reconstruction of the ACL. Operative treatment included three ACL reconstructions using hamstring tendons and two with quadriceps patellar tendon. All involved a centrally placed 6-mm or smaller tibial drill hole through an open physis and graft placement in an over-the-top position on the femur. At an average follow-up of 7.4 years (range, 4.5 to 9.9 years), no patient had a positive anterior drawer, Lachman, or pivot shift test. On KT-1000 arthrometer testing, all patients had 3 mm or less of increased anterior-posterior displacement (mean +/- SD = 1.0 +/- 1.6 mm). Magnetic resonance imaging showed that four tibial physes had fused in a symmetric fashion and one was still open. Orthoroentgenograms showed that no patient had a significant leg length discrepancy (-0.8 mm +/- 3.4 mm). The mean increase in height postoperatively was 17.7 cm (range, 7.6 to 31.0 cm). Overall, using the International Knee Documentation Committee (IKDC) evaluation form, there were four patients with grade A and one with grade C. The one patient with a poor IKDC grade had sustained a subsequent patellar dislocation with osteochondral fracture. In conclusion, ACL reconstruction using small drill holes placed through open tibial physes does not seem to adversely affect outcome or future growth.     

Deterioration of mechanical properties of the autograft in controlled stress-shielded augmentation procedures. An experimental study with rabbit patellar tendon

Effects of partial and complete stress shielding on mechanical properties and histology of in situ frozen patellar tendons were studied in 120 mature female Japanese White rabbits that were divided into three groups: completely stress-shielded, partially stress-shielded, and sham-operated groups. In the former two groups, tendon tension was reduced to 0% and about 30% of normal force, respectively, with a polyester artificial ligament. Tensile tests were conducted on patella-patellar tendon-tibia complexes harvested 1, 2, 3, 6, or 12 weeks after surgery. Tensile strength significantly decreased compared with the sham group to 17% and 28% at 3 and 6 weeks, respectively, in the completely stress-shielded group, and to 54% and 63% at 3 and 12 weeks, respectively, in the partially stress-shielded group. Patellar tendon cross-sectional area significantly increased to 156% and 157% at 2 and 3 weeks, respectively, in the completely stress-shielded group and to 133% at 2 weeks in the partially stress-shielded group, compared with the sham group. Stress shielding significantly changed tensile strength, tangent modulus, and cross-sectional area of in situ frozen patellar tendon; these changes depended on degree of stress shielding. Histologic observations indicated that remodeling occurred in the patellar tendon while there were no cells in the fascicle.     

Evidence that carbon monoxide stimulates prostaglandin endoperoxide synthase activity in rat hypothalamic explants and in primary cultures of rat hypothalamic astrocytes

Freezing or freeze-drying and gamma-irradiation are techniques currently used for processing tendon allografts. However, it is still unknown how these processing methods affect graft remodeling. In this study, we used a rat patellar tendon transplantation model to investigate the effect of various processing methods on remodeling by quantifying loss of collagen labeled with a radioactive isotope. The grafts were divided into the following four groups according to the processing method: fresh-frozen, freeze-dried, fresh-frozen and gamma-irradiated, or freeze-dried and gamma-irradiated. The percentage of donor collagen, calculated from hydroxyproline content and radioactivity level, was used as an indicator of graft remodeling. At 2 weeks, the level of donor collagen in the fresh-frozen group was 62%; in the freeze-dried group, 59%; in the fresh-frozen and irradiated group, 57%; and in the freeze-dried and irradiated group, 44%. At 4 weeks, the percentage of donor collagen remaining in grafts decreased to 38% in the fresh-frozen group, 19% in the freeze-dried group, 27% in the fresh-frozen and irradiated group, and 12% in the freeze-dried and irradiated group. Finally, at 12 weeks, the levels were 19% in the fresh-frozen group, 20% in the freeze-dried group, 15% in the fresh-frozen and irradiated group, and 6% in the freeze-dried and irradiated group. The percentages of donor collagen in the freeze-dried and the fresh-frozen and irradiated groups were significantly lower than that in the fresh-frozen group at 4 weeks. The values for the freeze-dried and irradiated group were significantly lower than those for the fresh-frozen and irradiated group at 4 and 12 weeks. These data suggest that freeze-drying, freeze-drying followed by gamma-irradiation, and fresh-freezing followed by gamma-irradiation temporarily accelerate graft remodeling.     

Anterior cruciate ligament graft fixation. Initial comparison of patellar tendon and semitendinosus autografts in young fresh cadavers

The initial biomechanical properties of semitendinosus and patellar tendon autografts and their fixation strengths were investigated. Twenty fresh cadaveric knees from donors under 42 years of age were used in the study. After removing all soft tissues other than the anterior cruciate ligament, we determined the ultimate tensile strength (2195 +/- 427 N) and stiffness (306 +/- 80 N/mm) of the anterior cruciate ligament in nine knees. In six knees, anterior cruciate ligaments were reconstructed using an autologous patellar tendon graft with proximal and distal interference fit screws; this resulted in an ultimate tensile strength of 416 +/- 66 N. Five knees were reconstructed with quadruple-stranded (double-looped) semitendinosus tendons fixed proximally by a titanium button and braided tape and distally by tibial post screw. This resulted in an ultimate tensile strength of 612 +/- 73 N, which was significantly higher than the strength in the patellar tendon group. Graft stiffness did not differ between the groups and was 47 +/- 19 N/mm (N = 11). This study demonstrates that the reconstructed knees had only 20% to 30% of the ultimate tensile strength of the normal anterior cruciate ligament. In summary, the semitendinosus reconstruction using a button for proximal fixation is, at the time of surgery, approximately 50% stronger than patellar tendon reconstructions with similar stiffness.     

Effect of external extra-articular ligament plasty on the results of anterior cruciate ligament reconstruction with patellar tendon, a 4 years follow-up

PURPOSE OF THE STUDY: The purpose of this study was to compare the functional results obtained when an external extra-articular plasty was added to an anterior cruciate ligament (ACL) reconstruction using an autologous bone tendon-bone patellar tendon graft. MATERIAL AND METHODS: The authors analyzed two consecutive series of 60 and 50 patients operated by the same surgeon for a chronic rupture of the anterior cruciate ligament, one by reconstruction of the cruciate ligament with a free graft of the patellar tendon supplemented by an external extra-articular plasty made with a quadriceps tendon graft and the second with an isolated free patellar tendon graft. Anterior laxity was measured before and after surgery, by dynamic X-rays and by the Medmetric KT-1000 arthrometer. Functional results were evaluated four years after operation, with the French A.R.P.E.GE score based on sport activity level and intensity. RESULTS: Anterior laxity was not different before operation in both groups and there was no difference between males and females. Medmetric KT-1000 arthrometer showed the same negative differential laxity immediately after surgery in both groups and the same evolution during the first 4 years, without any significant difference on laxity on the middle aspect of the knee. Radiological results were different. After a 4 years follow-up, anterior laxity did not show significant difference on the medial compartment of the knee (5.3 +/- 2.3 mm and 5.5 +/- 1.7 mm), but there was a significant minor laxity in the lateral compartment for the lateral extra-articular plasty group (11.0 +/- 2.3 mm against 14.8 +/- 3.8 mm)(p = 0.002). Functional results and sport activity were similar in both groups. Examination showed 4 positive pivot shift tests (2 "sliding" and 2 positive) in the group with extra-articular plasty, even though 8 positive pivot shift tests in the isolated ACL group (5 "sliding" and 3 positive) were found. DISCUSSION: This study, as well as five others studies found in literature, was not randomized. In all these series, the surgical techniques, the rehabilitation programs and the functional score evaluation were too different to allow any pertinent comparison. Extra-articular plasty helps to control the laxity of the lateral compartment of the knee which is incompletely controlled by ACL reconstruction, particularly in chronic cases. This is proved by radiological measurements and pivot shift tests. Jensen in 1983, about 205 patients with a 4 year follow-up and Noyes, which used an allograft patellar tendon, found an advantage to do extra-articular plasty. But Strum (in 1989), as O'Brien (in 1991) and Roth (in 1987), did not found any advantage with extra-articular plasty. CONCLUSION: It is therefore obvious, after a four-year follow-up, that extra-articular supplementation presents an advantage for reconstruction of the ACL. by a free graft of the patellar tendon in chronic cases. Further randomized study will confirm that isolated ACL reconstruction is possible in some well defined categories of anterior laxity.     

Effect of alignment of the transplanted graft extracellular matrix on cellular repopulation and newly synthesized collagen

This study examines the effect of alignment of the transplanted graft extracellular matrix on cellular repopulation and new collagen synthesis. The lateral half of the patellar tendon was harvested as a tendon graft from Lewis rats and frozen at -80 degrees C. In order to maintain the original alignment of the graft extracellular matrix, the graft was transplanted to a same size defect in the patellar tendon of other Lewis rats (group I). For controls, the graft was transplanted in a lax condition after excision of only the distal half of the lateral side of a patellar tendon (group II). After transplantation, six animals in each group were killed at 3, 7, 14, and 28 days. Cellular repopulation was assessed by using fibrillar-actin (F-actin) labeling with rhodamine-phalloidin, and new collagen synthesis was detected by means of a polyclonal antibody against type III collagen aminopropeptide (pN collagen III). Collagen fibril profiles were observed under the transmission electron microscope. On the 3rd day after transplantation, no specific fluorescence was detected in either group. Specific labeling for F-actin and pN collagen III, however, was observed at both ends of the graft in both groups at 1 week and throughout the graft at 2 weeks after transplantation. Consistent with the actin bundles' orientation, pN collagen III was aligned parallel to the longitudinal axis of the graft in group I. Collagen fibrils with a smaller diameter, mixed evenly and everywhere with a larger diameter, increased gradually in group I. However, smaller collagen fibrils in group II increased more slowly and were distributed unevenly. In summary, the dense collagen arrangement in the native patellar tendon determined the alignment of the repopulating cells, and the distribution of newly synthesized collagen might be affected by the actin cytoskeleton within the repopulating cells.     

The Ranawat Award. Comparison of surgical approaches in total knee arthroplasty

A series of 123 revision total knee replacements performed at three centers and followed up for 2 to 4 years was evaluated. In cases in which exposure could be obtained with undue tension on the patellar tendon, the surgical approach was modified using either quadriceps turndown (14 cases) or tibial tubercle osteotomy (15 cases). The remaining 94 patients underwent a standard operative approach that consisted of a medial parapatellar capsular incision which in 31 cases was combined with a quadriceps snip. The results were compared using the Knee Society clinical score, a patient satisfaction survey, and a patellofemoral questionnaire. Postoperatively, the group of patients who had a quadriceps snip was equivalent to the group of patients who underwent a standard approach in every parameter measured, and the groups therefore were combined for comparison purposes. The patients who had quadriceps turndown and the tibial tubercle osteotomy had equivalent scores postoperatively both of which were significantly lower than the standard group. The group of patients who had quadriceps turndown had a significantly greater increase in arc of motion than the tibial tubercle osteotomy group. The tibial tubercle osteotomy group had a lower degree of extension lag but a higher percentage of patients who had difficulty with kneeling and stooping and a higher percentage of patients who had difficulty with kneeling and stooping and a higher percentage of patients who thought the surgery was unsuccessful in relieving pain and unsuccessful in returning them to normal daily activities.     

Design of hypoxia-targeting radiopharmaceuticals: selective uptake of copper-64 complexes in hypoxic cells in vitro

A freehand technique of patellar resurfacing using anatomic references was prospectively evaluated. This technique utilizes an osteotomy beginning at the inferior pole of the patella just posterior to the insertion of the patellar tendon and is carried proximally posterior to the insertion of the quadriceps tendon. Evaluation of 55 total knee arthroplasties in 41 patients showed an average restored patellar thickness within 0.1 mm. The overall patellar thickness was restored to within 1 mm of its preoperative thickness in 50 (91%) of 55 knees. Patellar tilt was equal to or less than 4 degrees in 42 (89%) of 47 arthroplasties evaluated radiographically. The patellar thickness averaged 17.9 mm, well above the critical value of 15 mm reported in the literature.     

Extensor mechanism reconstruction with an allograft after total knee arthroplasty

The authors report on a series of 15 knees in which an extensor mechanism allograft was used to treat a rupture of the patellar tendon associated with a total knee arthroplasty. Nine of the knees have greater than two-year follow-up evaluation (average, 4.1 years; range, 2.3-7 years). Postoperatively, the average flexion was 106 degrees. All but three patients achieved full passive extension. Six of the nine knees had no extensor lag. The average post-operative clinical score for the follow-up group was 78 points. Graft complications include one early graft rupture, one early quadriceps junction failure, and one patellar component loosening. One graft fractured after revision of a metal-backed patella.     

The effect of exercise and rehabilitation on anterior-posterior knee displacements after anterior cruciate ligament autograft reconstruction

We studied the effect of rehabilitation strength training and return to activities on anterior-posterior knee displacements after patellar tendon autogenous anterior cruciate ligament reconstruction. A total of 938 measurements were sequentially collected for 142 patients with the KT-2000 arthrometer. Rehabilitation included immediate knee motion and early weightbearing, light sports at 6 months, and competitive sports at 8 months or later. At a minimum of 2 years after surgery, 121 patients (85%) had normal displacements (less than 3 mm of increase at 134 N), 14 (10%) had 3 to 5.5 mm of increase (partial function), and 7 (5%) had more than 5.5 mm of increase (failed). There was no association found between the initial onset of the abnormal displacements in the 21 knees and either the amount of time after surgery or the rehabilitation program. Six of the seven grafts that failed did so in the 1st postoperative year. Serial displacement measurements allow early detection of graft stretching and subsequent modification of rehabilitation or delay in return to strenuous activities. These measurements showed that the rehabilitation program used in this study was not itself injurious and resulted in an acceptable failure rate of 5%.     

Anterior cruciate ligament reconstruction and joint dynamics during stair climbing

Athletes with anterior cruciate ligament (ACL) deficiencies exert decreased knee extension moments during level walking (quadriceps avoidance gait), and yet within a few months of ACL reconstruction they are often expected to return to competitive sport. To investigate this issue further, 10 normal subjects and seven ACL deficient patients were evaluated both pre- and post-operatively (mean follow-up of 6 months), and each performed multiple trials ascending a staircase which consisted of three steps. Bilateral joint angles, moments, powers, and work were measured and the data were ensemble averaged and statistically analyzed (repeated measures ANOVA with significance level set at 0.05). Anterior-posterior knee laxity decreased significantly (from 7.9 mm to 5.8 mm) while subjective knee function also improved following ACL reconstruction (knee score increased from 70.4 to 88.5). Pre-operatively, there were no statistically significant differences in biomechanical parameters between the patients' ACL-deficient and intact sides and the normal subjects. Post-operatively, however, statistically significant reductions were seen for the peak moment (91.9 vs 22.5 Nm), power (181 vs 84 W), and work performed (28.0 vs -5.6 J) at the injured knee, which was also the knee from which the patellar tendon graft had been harvested. These reductions were accommodated by significant increases in excursion, moment, and power at the contralateral ankle joint. The results indicate that while the ACL reconstruction were successful in restoring anterior-posterior knee stability, the decrease in knee power and work performed post-operatively by the injured (i.e., donor) knee suggests that donor site morbidity may need to be critically evaluated over a long-term period.     

Effect of medial displacement of the tibial tubercle on patellar position after rotational malposition of the femoral component in total knee arthroplasty

A large Q angle induced by technical error such as an internally rotated femoral component causes patellar failure after total knee arthroplasty. The effect of medial displacement of the tibial tubercle to decrease the Q angle for patellar tracking was studied by evaluating the patellar position relative to the patellar groove on the femoral component in cadaver specimens. A 5 degrees internally rotated femoral component caused the patella to shift medially about 5 mm, and also caused the tibia to rotate internally about 3 degrees at full extension. With a 5 degrees externally rotated femoral component, normal patellar tracking occurred. The distance of medial displacement was determined so that the patellar tendon was parallel to the longitudinal axis of the tibia at full extension. This allowed the quadriceps tendon, the patella, and the patellar tendon to form a straight line. The average distance of medial transposition of the tibial tubercle was 9.32 mm. Medialization of the tibial tubercle caused the patella to shift about 2 mm medially from the patellar groove. The transfer also caused an external rotation of the tibia (2 degrees-5 degrees). Medial transfer of the tibial tubercle changes patellar kinematics and corrects the tendency toward lateral patellar dislocation caused by internally rotating the femoral component; however, it also creates minor patellar and tibial kinematic changes that may have a clinical effect.     

Is apoptosis a "programmed cell death"?]

The purpose of this study was to evaluate the results and complications of anterior cruciate ligament surgery in middle-aged patients. Forty-five consecutive patients over 40 years old (average age, 44.6 years) who had arthroscopically assisted anterior cruciate ligament reconstructions with midthird patellar tendon autografts were evaluated. The patients returned for interviews, physical examinations, radiographs, Biodex dynamometer strength testing, and KT-1000 arthrometer testing at an average of 37 months after their surgeries (range, 24 to 96 months). The mean Lysholm and Gillquist score was 91, which corresponds to symptoms only with vigorous activity. The overall scores from the International Knee Documentation Committee form were 29 (64%) normal or nearly normal and 2 (4%) severely abnormal. Side-to-side differences as determined by the KT-1000 arthrometer were < or = 3 mm in 31 of 40 patients (78%), between 3 and 5 mm in 4 patients (10%), and > 5 mm in 5 patients at 30 pounds of anterior displacement. Seventy-six percent of the patients (N = 34) returned to their preoperative activity levels. Three patients required repeat arthroscopic surgery for persistent knee pain and two patients had graft ruptures. This study shows that when middle-aged patients undergo surgery, their results can be successful and satisfying to a degree similar to those of younger patients.     

Prospective preoperative evaluation of anterior cruciate ligament instability of the knee joint and results of reconstruction with patellar ligament

Of 54 patients with chronic (n = 49) or acute (n = 5) anterior cruciate ligament instability, 52 were evaluated after mean 16 months' follow-up interval after open (n = 18) or arthroscopic assisted (n = 36) bone-tendon-bone patellar ligament reconstruction. Preoperative Knee Signature System side-to-side difference in anterior displacement decreased from 7.9 mm to 3.5 min at follow-up evaluation (p < 0.0001). An objectively satisfactory limit of 5 mm in side-to-side difference was achieved in 73% of the patients. At follow-up evaluation, there was a positive pivot shift sign in eight knees (one definite and seven trace). Average Lysholm knee scores improved from 69 to 83. The only significant difference between the arthroscopic assisted and open groups was smaller side-to-side anterior displacement difference in the arthroscopic group (2.2 mm versus 4.8 mm, p = 0.002). Results suggest that more accurate and isometric placement of the graft is possible with the arthroscopic-assisted technique.     

Differential effects of infection with a Babesia-like piroplasm, WA1, in inbred mice

To investigate the "rapid-adaptation" phenomenon, we examined force, neural, and morphological adaptations in 12 subjects who performed 100 eccentric contractions with the quadriceps muscle (bout 1) and repeated the same exercise after a 2-wk hiatus (bout 2). Two days after bout 1, quadriceps muscle strength and surface electromyographic (EMG) activity declined approximately 37 and 28%, respectively, in the control group (n = 6). At day 2 after bout 1, significant increases occurred in patellar tendon reflex amplitude (approximately 25%), muscle soreness (fivefold), and serum creatine kinase (220%), and 65 +/- 12% of the total number of pixels in the EMG indicated myofibrillar disruption. At day 7 after bout 1, all variables returned to normal. At day 2 after bout 2, no significant changes occurred in force, EMG, creatine kinase, or soreness, but reflex amplitude increased, and 23 +/- 4% of the total number of pixels in the EMG still indicated myofibrillar disruption. The results suggest that the rapid force recovery following eccentric exercise is mediated at least in part by neural factors and that this recovery may occur independently of cell disruption.     

Detection of IgM against the dengue++ virus in whole blood absorbed on filter paper]

Thirty-four sheep were submitted to surgery substituting the native ACL with the central third of the patellar tendon, ten enter this study. The purpose was to find a possible relationship between tissue pO2 and healing processes considering also the biomechanical and histomorphological aspects of the grafts. Four of them were sacrificed under general anaesthesia after 6 months, and six after 1 year in order to perform tissue pO2 measurement and an analysis of microvessel density on specimens of the normal ACL and the graft. Our data showed higher pO2 values of the autografts after 6 months. After 1 year the data was comparable to those of native ACL. This was confirmed by a microvessel count of the histological specimens and the data was in relationship to biomechanical and histomorphological analysis. Tissue pO2 can be observed and recorded in "in vivo" ACL, and patellar tendon used as graft, with no injury to their integrity. The monitoring system might be considered as an experimental tool for indirect controls of the anterior cruciate substitutes.