Method for establishing and measuring in vivo forces in an anterior cruciate ligament composite graft: response to differing levels of load sharing in a goat model

In order to determine the appropriate load history for optimal remodeling of an anterior cruciate ligament graft, methods for establishing and measuring the graft force due to an external load could be set to a preselected value in in vivo are required. Our objectives with this study were to (a) develop a method in which the graft force due to an external load could be set to a preselected value in a living animal, (b) show that this force could be maintained after fixation, and (c) determine what happens to the forces after the animal has functioned for as long as 2 weeks postoperatively, when differing levels of load sharing between the segments had been set at surgery. The anterior cruciate ligament was reconstructed in 12 goats with use of a bone-patellar tendon-bone graft and a synthetic augmentation device. The forces in the graft segments were established, at the time of surgical fixation, with use of a force-setting technique. In five animals, the tendon segment was set to carry 90% of the total graft force; in the remaining seven animals, the augmentation segment was set to share 90% of the total graft force. Graft forces were measured, with the use of buckle transducers mounted extra-articularly over the anterior tibia, under a 67 N anterior tibial load at 60 degrees of knee flexion before and after fixation and at 2 weeks postoperatively.(ABSTRACT TRUNCATED AT 250 WORDS)     

Placental restriction alters adrenal medullary development in the midgestation sheep fetus

This is a retrospective study of 10 patients with combined cruciate ligament and posterolateral instability who underwent surgical reconstruction between 1991 and 1994. All knees had at least 20 degrees increased external rotation at 30 degrees of knee flexion and from 1+ to 3+ varus instability. Five knees with posterior cruciate ligament ruptures had at least a 2+ Lachman test result. (One knee had both anterior and posterior cruciate ligament injuries). In all cases the lateral collateral ligament was reconstructed with a bone-patellar tendon-bone allograft secured with interference screws. Fixation tunnels were placed in the fibular head and at the isometric point on the femur. The cruciate ligaments were reconstructed with autograft or allograft material. The average follow-up was 28 months. Excessive external rotation at 30 degrees of flexion was corrected in all but one knee. Six patients had no varus laxity, and four patients had 1+ varus laxity at 30 degrees of flexion. The posterior drawer test result decreased, on average, to 1+, and the Lachman test result decreased to between 0 and 1+. The average Tegner score was 4.6, with five patients returning to their preinjury level of activity and four returning to one level lower. These results indicate that this is a promising new procedure for patients with instability resulting from lateral ligament injuries of the knee.     

Revision of failed prosthetic anterior cruciate ligament reconstruction

Revision of failed prosthetic anterior cruciate ligament reconstructions will continue to be necessary as previously placed prosthetic devices fail with time. These patients often present with recurrent instability, pain, swelling, or effusions. Graft rupture and the generation of particulate debris are common causes of these symptoms. To effectively treat these patients requires careful preoperative evaluation and planning. Operative treatment includes removing the prosthesis and metal fixation devices, evaluating femoral and tibial bone stock, and determining adequacy of previous tunnel position. Staging of the operation may be a necessity if significant bone loss or poor tunnel position on either the femoral or tibial side requires bone grafting. The use of an autogenous bone-patellar tendon-bone graft is suggested and has proven to be effective in restoring knee stability in these revision cases. The ultimate outcome following revision of failed prosthetic ligaments may be limited by associated intraarticular pathology often seen in this patient population.     

Thermal injury functionally alters bone marrow-derived macrophages: a study of monocyte-hepatocyte interactions

PURPOSE OF THE STUDY: The purpose of this study was to evaluate the results of the anterior cruciate ligament (A.C.L.) reconstruction according to two scoring systems (Arpege and IKDC), to analyse the influence of different factors on the results, to study the effect of a lateral extra-articular tenodesis, the morbidity of patellar tendon graft harvesting, and the advantage of arthroscopically assisted reconstruction. MATERIAL: Seventy nine patients, 17 to 39 years old (average 27 years), underwent an anterior cruciate ligament reconstruction for chronic instability, using a free bone-patellar tendon-bone graft. In 43 cases, a lateral extra-articular plasty was added (Lemaire's procedure). The reconstruction was arthroscopically assisted in 17 cases. Interval between initial injury and surgery was 24 months (2 months to 9 years and 7 months). The average follow-up was 2.5 years (range 1 to 18). METHOD: All patients were reviewed for evaluation with two scoring systems (Arpege and IKDC). Roentgenograms of both knees, including antero-posterior weight-bearing and lateral view, patellar view, dynamic radiographs, allowed evaluation of post-operative arthrosis and residual anterior laxity in extension. Fischer's test and chi square test were used for statistical evaluation. RESULTS: Using the Arpege CLAS system, functional results were excellent or good in 75.9 per cent of cases (excellent in 44.3 per cent, good in 31.6 per cent), fair in 15.2 per cent, poor in 8.9 per cent; according to the IKDC system, 65.8 per cent were excellent or good. 84.8 per cent of the patients were satisfied in Arpege system and 91.2 per cent in IKDC system. The pivot-shift test was negative in 86 per cent, equivocal in 7.6 per cent and positive in 6.4 per cent. The radiological Lachman's test (difference between control and affected knee) was 0-2 mm in 53.2 per cent, 3-5 mm in 39.2 per cent, 6-10 mm in 7.6 per cent, never greater than 10 mm. Antero-posterior weight-bearing radiographs were normal in 83.5 per cent, showed joint remodeling in 10.1 per cent pre-arthrosis in 6.3 per cent but no arthrosis. Functional results were not correlated with age at time of surgery, interval between initial injury and surgery, nor clinical Lachman's test. Competitive sportsmen had a better result (p = 0.001). Residual laxity in extension was correlated with lesions of medial meniscus (p = 0.035). Degenerative changes in femoro-tibial joint were correlated with residual laxity in extension (p = 0.019). There was no significative difference between A.C.L. reconstruction isolated or associated with lateral extra-articular tenodesis. Time to return to work was shorter for patients with arthroscopically assisted procedure (p = 0.067). DISCUSSION AND CONCLUSION: Functional results after A.C.L. reconstruction using a free bone-patellar tendon-bone graft are satisfactory and confirm the reliability of this procedure. Arpege CLAS and IKDC systems give comparable functional results, but IKDC evaluate anatomical results, residual laxity and degenerative changes of the joint, that constitute essential long-term pronostic factors. Morbidity of patellar tendon harvesting appears to be of short duration and largely reversible. Added lateral extra-articular tenodesis doesn't improve the results. Arthroscopically assisted procedure seems to allow a faster rehabilitation.     

Anterior cruciate ligament reconstruction. Bone-patella tendon-bone versus semitendinosus anatomic reconstruction

In this article, the long term (2-10 years; mean, 4.8 years) followup results of two reconstructive procedures for the anterior cruciate ligament are compared. The bone-patella tendon-bone (with interference fit fixation) was performed on 69 knees, and the semitendinosus anatomic reconstruction was performed on 68 knees, in a population of 76 men and 52 women (age range, 15-60 years; average, 31 years). The patients in the two groups showed no difference in subjective results or activity level and no significant difference to manual testing. The semitendinosus procedure group had a slightly higher KT manual maximum failure rate than the patella tendon group (17% versus 11%). Arthrometric stability did not show deterioration, but patient satisfaction decreased in those patients who had meniscectomies. Both procedures showed satisfactory results during the long term followup. However, if the secondary restraints are compromised, the stiffer bone-patella tendon-bone construct is preferred for reconstruction of the chronic anterior cruciate ligament deficient knee.     

Outpatient ACL reconstruction using intraoperative local analgesia and oral postoperative pain medication

Thirty-five consecutive anterior cruciate ligament (ACL) reconstructions were performed in an ambulatory surgical unit using a bone-patellar tendon-bone autograft. Patients were evaluated postoperatively to determine the amount of pain medication used, the readmission rate, postoperative complications, and cost. Outpatient ACL reconstruction led to a savings of $4700 compared with the cost of performing the same procedure in a hospital operating room with an overnight admission. This study demonstrates that outpatient ACL reconstruction, using local analgesia intraoperatively and oral narcotic pain medication postoperatively, is a safe and cost-effective procedure with minimal to no morbidity.     

Regulation of melatonin synthesis in rainbow trout (Oncorhyncus mykiss) pineal organs: effects of calcium depletion and calcium channel drugs

In a double-blind, randomized trial, 40 patients undergoing open anterior cruciate ligament (ACL) reconstruction using a bone-patellar tendon-bone autograft were randomly allocated to two groups: group A (n = 20) received an intra-articular instillation of 20 mL bupivacaine (0.25%) and a local infiltration of 20 mL bupivacaine (0.5%) 15 minutes before surgery. Group B (n = 20) received an injection of saline solution in the same manner. Patient-controlled on-demand analgesia (PCA) with intravenous piritramid was used for postoperative pain control. A significant decrease in pain scores on a visual analog scale (VAS scale, 0 to 10) was found in the bupivacaine group (group A) at bedrest on the day of surgery only (pain score, 5.5 v 7.3 (scale, 0 to 10), P < .05). At all other times, no significant differences were found. The overall supplemental opioid requirements were not different between the study groups (63.9 v 62.6 mg piritramid/72 hours). A long-lasting, clinically relevant, pain-reducing effect with infiltration of bupivacaine before surgery could not be shown with this study.     

Capillary closure secondary to retinal vein occlusion. A morphological, histopathological, and immunohistochemical study

This article describes a modified endoscopic technique of posterior cruciate ligament reconstruction using bone-patellar tendon-bone or calcaneus tendon allografts. Three portals were used: a parapatellar anteromedial portal, a lateral anterolateral portal, and a proximal posteromedial portal. The tibial tunnel was made through the anterolateral tibial cortex 2 cm lateral to the tibial tuberosity to the posterior flat spot of the tibia 1 cm below the articular margin and just lateral to the midline. By this method, a less acute angle at the turning point of the tibial tunnel and a straighter alignment of the graft in the coronal plane can be obtained. The femoral tunnel was made through the lateral anterolateral portal without incision over the medial femoral condyle to minimize the injury to the vastus medialis obliques muscle. The 25-mm long proximal bone plug was easily passed through the tibial tunnel using a specially designed suture pusher and guided into the femoral tunnel by pulling the leading suture with the knee flexed 30 degrees. Firm graft fixation was achieved with absorbable interference screws or staples.     

Seizures and the long-QT syndrome

We report a series of 20 athletes with an ossicle associated with Osgood-Schlatter's disease (OSD) who underwent anterior cruciate ligament (ACL) reconstruction using autogenous, central-10-mm patellar-tendon graft. All patients had an Osgood Schlatter's lesion with an ossicle as seen on a plain radiograph. The patients were reviewed at an average follow-up of 44 months (range, 24 to 108 months). The postoperative assessment included clinical examination, KT-1000 testing, isokinetic testing, and subjective score (using the modified Noyes' questionnaire). At the time of latest review, all 20 patients had a stable knee. The average side-to-side difference on manual maximum KT-1000 assessment was 1.9 mm (range, 0 to 5 mm). Average time to return to full sporting activities was 5.2 months (range, 2.6 to 8.9 months). All patients returned to their previous level of activity. The mean modified Noyes' knee score was 96 (range, 89 to 100). To date, no graft failure has occurred. Based on the results of this study, we believe that ACL reconstruction using the autogenous bone-patellar tendon-bone graft can be safely undertaken in athletes with an ossicle associated with OSD without compromising the final knee function.     

Augmented anterior cruciate ligament replacement with the Kennedy-LAD (ligament augmentation device)--long term outcome

The ligament augmentation device (Kennedy-LAD) is used to protect tendon grafts during the posttransplantation decrease in strength in anterior cruciate ligament (acl) reconstructions. The augmentation with the LAD is based on the concept of load sharing. Since 1983 we used the LAD in acl-reconstructions in 856 patients. In 63 cases we had to treat complications like infection (8), recurrent effusions (21), arthrofibrosis (34). The overall results are good with respect to stability, regain of strength and sports activity. In 73 cases resurgery was necessary because of synovitis (7), LAD-rupture due to re-injury (9), fatigue-rupture of the LAD (22), meniscal tears (35), 2.7 +/- 2.3 years (range: 2 months to 10 years) after LAD implantation. Modern techniques in acl reconstruction lead to comparable results without synthetic augmentation. Therefore, we now recommend the use of a LAD only in cases of repeated acl replacement with week tendon grafts, to avoid an allograft.     

Correlation of remaining patellar tendon width with quadriceps strength after autogenous bone-patellar tendon-bone anterior cruciate ligament reconstruction

One hundred twenty-one patients were prospectively studied to determine whether the different remaining patellar tendon widths after central 10-mm bone-patellar tendon-bone graft harvest influenced the rate and level of quadriceps strength achieved during rehabilitation. Size of the patellar tendon width, measured at the same location in each patient, ranged from 24 to 35 mm. For this study, patients were grouped according to their remaining tendon size into small (14 to 17 mm; mean, 15.8), medium (18 to 20 mm; mean, 19.2), and large (21 to 25 mm; mean, 22.5) widths. Postoperatively, the patient's isokinetic quadriceps scores were determined at 6 weeks, 3 months, 6 months, and 1 year. At 6 weeks, the small- and medium-width tendon groups were significantly weaker than the large-width tendon group. At 3 months, only the small-width tendon group continued to be significantly weaker than the large-width tendon group. At and beyond 6 months, no statistically significant differences were seen between remaining patellar tendon width groups and their isokinetic quadriceps scores. A constant-sized autogenous patellar tendon graft may be harvested for anterior cruciate ligament reconstruction without compromising ultimate postoperative quadriceps strength recovery.     

Therapy of posterior and posterolateral knee instability

The natural course after posterior cruciate ligament (PCL) tear is a slow process of degeneration starting in the medial compartment. Functional disability is mainly present in those instabilities that are combined with posterolateral insufficiency. The surgical treatment at present mainly addresses these combined types of posterior-posterolateral instability. It is generally agreed that suture of the torn PCL alone is insufficient and augmentation with autologous structures, such as the patellar ligament, are mandatory. Synthetic augmentation to facilitate after treatment is another adjunct. Because of the difficulty of precise tibial tunnel placement a two-stage procedure is advocated, an anterior approach with the patient supine being used for femoral graft placement. If a posterior approach with the patient prone is used, a straight posterior incision is made between the two heads of the gastrocnemius and the neuromuscular bundle. With this approach the tibial bone block is placed in a trough. The accuracy of graft placement and the immediate functional aftertreatment facilitated by the use of osseous fixation of a synthetic augmentation device at both ends have made better results of surgical reconstruction of the PCL possible.     

Augmentation techniques: are they out?

Basics of ligament augmentation are reviewed from the literature. As biomechanical in-vitro studies, animal experiments, and clinical studies show different designs and data, the results may be interpreted variably. Theoretically there is a positive effect of augmentation, but no significant improvement of clinical results is evident. The goal of our own prospective study was to check the healing capacity of a repaired and augmented ACL with respect to stability compared to a primary or secondary BTB ligament replacement with and without augmentation. 200 patients were allocated to 4 groups. In group I (G1) acute proximal ruptures were repaired arthroscopically and augmented with PDS II-cord. Patients in G2 received an acute and in G3 a late BTB ligament replacement. Additionally in G4 a late ligament replacement was augmented with a PDS II-cord. The clinical results reveal a comparative stability between G1 and G2, and gradually less stability in G3 and G4. Subjectively, knee function was felt best in G1 and G2 while being worst in G3 and G4. There is no significant difference in the mobility of knees between primary and secondary ligament replacement. An additional augmentation doesn't improve the knee stability. CLINICAL RELEVANCE: There is no positive effect of an augmentation technique of a biologic ligament replacement concerning stability, morbidity, complication rate, and costs. Very marginal freshly ruptured cruciate ligaments may be reinserted successfully by a biodegradable augmentation. Subjective feeling and functional stability may be at least equal to a primary ligament replacement. There are no advantages in knee mobility, when a secondary ligament replacement is performed.     

A feasibility study evaluating rhBMP-2/absorbable collagen sponge device for local alveolar ridge preservation or augmentation

This two-center human clinical trial evaluated recombinant human bone morphogenetic protein-2 delivered in an absorbable collagen sponge (rhBMP-2/ACS) for either alveolar ridge preservation after tooth extraction or augmentation of localized osseous defects. This 24-month study comprised two parts: a 4-month acute safety and bone induction period (Part I) followed by a 20-month, osseointegration, functional restoration, and long-term safety evaluation (Part II). The primary objective of Part I, discussed in this article, was to evaluate the short-term safety and technical feasibility of the rhBMP-2 device implantation. Twelve patients (six preservation and six augmentation) were enrolled in the investigation. Patient safety was monitored by oral examinations, radiographs, and the collection of blood samples to measure serum chemistries, hematology, and potential antibody formation. Technical feasibility was evaluated by collecting information relating to the handling properties of the rhBMP-2/ACS device. The ability of various evaluative tools to measure the bone-inducing activity of the rhBMP-2/ACS device was also assessed. The clinical results suggested that rhBMP-2/ACS was well tolerated locally and systemically, with no serious adverse events. The device was found to be easily handled and adapted to the ridge and extraction socket. Using direct measurements, all sites demonstrated firmness and fullness to palpation at 4 weeks; however, a loss of volume was noted in some treatment areas between 4 and 8 weeks. Augmentation of the alveolar ridge was not observed in the patients as assessed by the evaluation techniques. This trial indicated that the use of rhBMP-2/ACS to preserve alveolar ridge after tooth extraction or augmentation of localized defects is safe and feasible. Bone fill was observed in all alveolar sockets filled with the rhBMP-2 device.     

Chiari malformation and tonsillar ectopia in twin brothers and father with autosomal dominant spondylo-epiphyseal dysplasia tarda

Open reduction of the radial head and reconstruction of the annular ligament has been advocated for the Monteggia fracture dislocation in children who present more than a month after injury. Three patients with an anterior Monteggia lesion were treated by open reduction of the radial head which was held in place by a Kirschner wire passed from the humerus to the radius. No attempt was made either to repair or reconstruct the annular ligament. The patients were aged between 2 and 6 years, the delay between injury and reduction was between 6 and 8 weeks, and the length of follow up was 5 years for two patients and 1 year for the third. All three patients were free of pain, had no deformity and the radial head had not subluxated. All had nearly full flexion at the elbow. The forearm had full supination but restricted pronation.     

Repair of a deep digital tendon deficit in a horse using a polypropylene implant

A yearling horse was treated for a chronic wound with a 4 cm deficit in the deep digital tendon. The gap in the tendon was bridged with paired polypropylene braided implants designed for use as a ligament augmentation device. Uncomplicated healing and return to function occurred.     

Experimental evaluation of various anchoring techniques for synthetic ligaments

One of the weak points of augmentation or replacement of cruciate ligaments by synthetic material is the fixation of these artificial ligaments to the bone. The present investigation examines the mechanical properties of a newly developed anchoring technique (ligament fixation device = LFD) in regard to linear and maximum load, stiffness, creep, and long-term durability compared to single staples, double staples in belt buckle technique, and passing the ligament through an additional bone tunnel. The tests are carried out on cadaver knees and plastic bones under standardized conditions with the same artificial ligament in all experiments (Trevira hochfest). The LFD shows a linear load of 1866 N in cadaver knees and 1874 N in plastic bones. The stiffness is 68.3 N/mm respectively 51.9 N/mm, the elongation at 500 N load 12.7 mm respectively 10.9 mm. In the hysteresis tests with submaximum loads the ligament/LFD-unit lasts 8515 cycles in the plastic bone and 4431 cycles in the cadaver knee. These results are significantly superior to all other fixation techniques concerning linear load, stiffness and long-term durability. They permit aggressive functional treatment and immediate postoperative weight bearing of the operated knee.     

Knowledge of diet and blood pressure among African Americans: use of focus groups for questionnaire development

The long-term results were reviewed for seventy-two patients (seventy-five knees) who had had a bone-patellar ligament-bone intra-articular reconstruction of the anterior cruciate ligament between August 1984 and May 1992. The mean age of the patients at the time of the operation was forty-five years (range, forty to sixty years). Three patients had a bilateral procedure. The primary mechanisms of injury were accidents that occurred during skiing (thirty-two knees), tennis (fourteen knees), and soccer (five knees). We analyzed the responses to subjective questionnaires, the functional results, and the objective clinical data. The clinical examination included assessment of the range of motion, performance of Lachman and pivot-shift tests, and measurements with use of a KT-1000 arthrometer. All knees were evaluated with use of three common rating scales: that of Lysholm and Gillquist; that of The Hospital for Special Surgery, as modified by Insall et al.; and the International Knee Ligament Standard Evaluation Form. At the latest follow-up evaluation, at a mean of fifty-five months (range, twenty-six to 117 months), three patients reported pain or swelling. No patient reported giving-way or symptoms related to the patellofemoral joint. The mean range of extension was -12 to 6 degrees, compared with -8 to 42 degrees preoperatively, and the mean range of flexion was 112 to 150 degrees, compared with 52 to 154 degrees preoperatively. Flexion was limited to 112 degrees in one patient, but this was 5 degrees greater than that of the uninvolved knee. Sixty knees (80 per cent) had a negative pivot-shift test, and ten knees (13 per cent) had a grade of 1+. On testing with the KT-1000 device at maximum manual pressure, the mean difference between the injured and uninjured knees was found to have improved by 5.1 millimeters, from 6.4 millimeters preoperatively to 1.4 millimeters postoperatively (p < 0.01). The grade on the International Knee Ligament Standard Evaluation Form improved markedly; seventy-two knees (96 per cent) had a grade of C or D preoperatively, whereas seventy knees (93 per cent) had a grade of A or B postoperatively. The Hospital for Special Surgery score improved from a mean of 69 points preoperatively to a mean of 92 points postoperatively (p < 0.01). The mean score according to the scale of Lysholm and Gillquist increased from a mean of 63 points preoperatively to a mean of 94 points postoperatively (p < 0.01). All patients indicated that they were pleased with the result of the procedure. Bicycling was resumed at a mean of four months; jogging, at a mean of nine months; skiing, at a mean of ten months; and tennis, at a mean of twelve months.     

Effects of high doses of theophylline on memory acquisition

Although tourniquets are used commonly during anterior cruciate ligament (ACL) surgery, little data are available regarding their effects on postoperative function. This retrospective study evaluated 94 patients who had an arthroscopically assisted, autogenous bone-patellar ligament-bone ACL reconstruction between 1988 and 1991 at the San Diego Kaiser Hospital. A tourniquet was used in 48 patients (T+ group). No tourniquet was used in 46 patients (T- group). The surgical and postoperative protocols were identical for the two groups. There were no bleeding complications. There was no significant difference in anesthesia time between the two groups. This study has shown that ACL surgery can be performed expeditiously without a pneumatic tourniquet. Quadriceps strength recovery after surgery was less in the T+ group at 12 weeks after surgery, but there was no significant difference between the groups 52 weeks after surgery. Difference in thigh girth was greater in T+ group 6 and 12 weeks after surgery, but there was no significant difference between the groups 52 weeks after surgery.     

The relationship of low voltage on the electrocardiogram and chronic obstructive pulmonary disease

A retrospective analysis was performed to analyze the relationship between low voltage on the electrocardiogram and chronic obstructive pulmonary disease. Subjects were 250 patients who had both pulmonary function tests and an electrocardiogram at UMDNJ-John F. Kennedy Memorial Hospital from the years 1975-1980. Low voltage was detected in only 13 of 250 patients. An attempt to define the relationship between the incidence of low voltage on the electrocardiogram and the severity of airway obstruction, as judged by the reduction in the FEV1, was unsuccessful. Concomitantly, a relationship could not be established between the incidence of low voltage and the degree of hyperinflation, as judged by the residual volume. In conclusion, the electrocardiographic evidence of low voltage does not represent either a sensitive or a specific finding for patients with chronic obstructive lung disease. It cannot be construed as either a useful or predictive parameter in the diagnostic evaluation of these patients.