Intraarticular anterior cruciate ligament graft placement on the average most isometric line on the femur. Does it reproducibly restore knee kinematics?

In the past, there has been a plausible hypothesis that anterior cruciate ligament graft placement at isometric sites, such that the tibial and femoral attachment sites remain equidistant from each other throughout knee range of motion, would increase the likelihood of a satisfactory outcome. For a given tibial placement we wanted to determine whether placing the graft on the average of the most isometric femoral line, a fixed distance from the outlet of the intercondylar notch, would return normal laxity to all knees. The three-dimensional kinematics of seven cadaveric knees were measured for angles from full extension to 90 degrees of flexion at 15 degrees increments. Physiologic levels of quadriceps muscle forces were applied to the intact knee, after transection of the anterior cruciate ligament, and after ligament reconstruction with a patellar tendon graft. On average, the reconstruction was found to return anterior-posterior translation, internal-external rotation, and varus-valgus rotation to levels not significantly different from those of the intact knee. However, the ranges of the translation and rotations were large. Placing the graft on the average most isometric femoral line did not restore knee laxity to normal in all knees. This supports the need to customize graft placement in each knee at the time of surgery.

The effects of removal and reconstruction of the anterior cruciate ligament on patellofemoral kinematics.

Patellofemoral pain may be associated with anterior cruciate ligament deficiency or may occur after anterior cruciate ligament reconstruction. We investigated the effects of the removal and reconstruction of the anterior cruciate ligament on the kinematics of the tibiofemoral and patellofemoral joints during physiologic levels of quadriceps muscle loads in seven cadaveric knees. A bone-patellar tendon-bone graft was used for intraarticular reconstruction of the anterior cruciate ligament. The spatial positions of the tibiofemoral and patellofemoral joints were measured between 0 degrees and 90 degrees of knee flexion in 15 degrees increments with a six degree-of-freedom digitizing system. Excision of the anterior cruciate ligament resulted in statistically significant increases in anterior tibial translation between 0 degrees and 90 degrees and valgus tibial rotation between 30 degrees and 90 degrees; intraarticular reconstruction returned these to levels not significantly different from those of the intact knee. Excision of the anterior cruciate ligament resulted in significant increases in lateral patellar tilt, ranging from 6.3 degrees to 9.0 degrees between full extension and 90 degrees of knee flexion, and in lateral patellar shift, ranging from 2.9 mm at 15 degrees of knee flexion to 5.9 mm at 90 degrees; intraarticular reconstruction returned these to levels not significantly different from those of the intact knee. Neither removal nor reconstruction of the anterior cruciate ligament significantly affected tibial internal-external rotation, patellar flexion, patellar mediolateral rotation, patellar anteroposterior translation, or patellar proximodistal translation.

Results of isolated patellar debridement for patellofemoral pain in patients with normal patellar alignment.

We reviewed the records of 36 patients who underwent arthroscopic patellar debridement for patellofemoral pain. All patients had isolated chondromalacia patellae noted during arthroscopic examination. No patient had a history of patellar instability or physical or radiographic signs of patellar malalignment. The chondromalacia patellae was classified as traumatic or atraumatic in origin. All patients had failed results after a minimum of 4 months of physical therapy before surgery, and all patients had grade 2 or worse chondromalacia patellae at the time of debridement. At the time of followup, patients were evaluated by questionnaire, Fulkerson-Shea Patellofemoral Joint Evaluation score, independent physical examination, and radiographs. Patients were also asked to subjectively score their knees preoperatively, at the time of maximal improvement postoperatively, and at the time of followup for comparison. Preoperative examinations and radiographs were compared with examinations at the time of followup. The most significant finding was the improvement in the overall joint evaluation score. The score for the entire group improved from a mean of 51.9 preoperatively to 78.8 at the time of maximal improvement and 75.3 at the time of followup. All but four patients subjectively thought that surgery had a beneficial effect. There were no observed changes in the preoperative and postoperative radiographs. Patients with traumatic chondromalacia patellae had 57.9% good or excellent results with surgery, and the patients with atraumatic cases had 41.1% good or excellent results with surgery, indicating that many patients who were improved by the surgery still had functional limitations.

The effects of knee reconstruction on combined anterior cruciate ligament and anterolateral capsular deficiencies.

We tested the effect of intraarticular reconstructions of the anterior cruciate ligament alone and in combination with extraarticular reconstructions in 10 cadaveric knees. These knees had anterior cruciate ligament deficiency alone or in combination with anterolateral capsuloligamentous deficiencies. In the knees with combined injury, intraarticular reconstruction returned anterior stability to levels not significantly different from levels found for the knees deficient in the anterior cruciate ligament alone and treated with this procedure. After intraarticular reconstruction, rotational stability of the knee with combined injuries failed to return to the levels seen in the knee with isolated anterior cruciate ligament deficiencies that underwent the same treatment. When a tenodesis with either 0 N or 22 N of tension was added to the intraarticular reconstruction in the knee with combined injuries, we found that excessive internal rotation significantly decreased at all angles of flexion, except at full extension with 0 N of tension. In addition, the extraarticular reconstruction with 22 N of tension in the tenodesis overconstrained the knee in internal rotation between 30 degrees and 90 degrees of knee flexion. The tenodesis with 0 N of tension overconstrained the knee at only 60 degrees and 90 degrees of flexion. These results suggest extraarticular reconstruction as an adjunct to the intraarticular operation for the knee with anterior cruciate ligament and anterolateral structural injuries. The results also suggest that the surgeon can affect anterior and rotational laxity by adjusting the tension in the tenodesis.

In vitro study of knee stability after posterior cruciate ligament reconstruction.

The effect of reconstructing the posterior cruciate ligament on anteroposterior laxity of the knee was evaluated in 7 cadaveric knees. A bone-patellar tendon-bone graft was used. Femoral pilot holes were drilled to locate the most isometric sites for attachment of the graft to the femur using an isometer. A tension of 89 N was set in the graft using a tensiometer with the knee in 90 degree flexion while applying an anterior drawer force of 156 N to the tibia. Posterior displacement of the knee was measured in 15 degree increments from O degree to 90 degrees in the intact knee, in the knee with the posterior cruciate ligament transected, and after reconstruction of the posterior cruciate ligament in response to 100 N of posteriorly applied force. Graft tension was nearly constant between 0 degrees and 90 degrees flexion, indicating the grafts to be isometric. The reconstruction reduced posterior translation of the tibia in the posterior cruciate ligament excised knee at all angles of flexion; the differences were statistically significant. The reconstruction returned posterior translation to levels not significantly different from those of the intact knee between 0 degrees and 45 degrees flexion but not in the greater angles of flexion tested.

Strategies for attachment site locations and twist of the intraarticular anterior cruciate ligament graft.

We modeled an intraarticular anterior cruciate ligament graft and investigated the effects of attachment orientation and twist of the graft on its isometry during quadriceps muscle loading. Physiologic levels of quadriceps muscle loads were applied to 15 intact cadaveric knees. We measured the changes in distance between points on the tibia and femur for knee flexion angles between 0 degree and 120 degrees using a three-dimensional digitizer. Selected points on the tibia and femur, representing graft attachment sites, allowed us to model the graft as a broad band. Distance was used to approximate graft fiber length. A 180 degrees twist in the graft significantly reduced the maximal range of changes in distance when the graft was attached in the anteroposterior direction. Range is defined as the difference between the largest and smallest changes in distance among the fibers of the graft for a given angle of flexion. This reduction enhanced isometry among the fibers of the graft. Enhanced isometry would be expected to enhance load sharing among these fibers, thereby increasing the overall strength of the graft. For a graft 10 mm wide and 4 mm thick, the dimensions of a typical patellar tendon graft, the best overall isometry was found when the breadth of the graft was attached to the tibia in the mediolateral direction, to the femur along the most isometric line, and with a 180 degrees twist in the graft.

Arthroscopic arthrolysis for flexion contracture following intraarticular reconstruction of the anterior cruciate ligament.

This article describes the surgical technique and expected results for arthroscopic arthrolysis for the treatment of flexion contracture following anterior cruciate ligament (ACL) reconstruction. The technique emphasizes a systematic approach to the surgical procedure followed by an intensive rehabilitation program. The results in 11 patients treated with this technique are reviewed. They averaged 12.6 months from the index ACL reconstruction. Despite extensive physical therapy, their mean preoperative flexion contracture was 19 degrees, mean total range of motion was 94 degrees, and mean preoperative Lysholm score was 67. At a mean follow-up of 22 months following arthrolysis and physical therapy, mean flexion contracture improved to 2 degrees, total range of motion improved to 125 degrees, and mean Lysholm score improved to 94.

Medial collateral ligament injuries in athletes.

Medial collateral ligament (MCL) sprains are tension injuries to the medial ligamentous structures of the knee. They are usually the result of an acute blow to the lateral aspect of the knee. The diagnosis can usually be made on the basis of a characteristic clinical examination. The treatment of these injuries has evolved over several years. Current recommended treatment for isolated MCL sprains is lightweight support and an aggressive early functional rehabilitation programme. In combined injuries, cruciate ligaments are usually surgically reconstructed and the MCL treated non-operatively. Although many braces have been developed to prevent MCL sprains, their effectiveness is uncertain.

Grip lock injuries to the forearm in male gymnasts.

We performed an epidemiologic survey to estimate the number of grip lock injuries occurring among male high school and college gymnasts. These injuries occur when dowel grips used by the gymnast become locked on the bar as the gymnast's momentum carries him through the skill being performed. We also questioned injured gymnasts to obtain details of their injuries. Thirty-eight high school coaches reported 17 injuries and 32 college coaches reported 21 injuries for a 10-year period; 36% of the coaches responding reported at least one such injury in their program. Of the 23 injured gymnasts who returned detailed questionnaires, 20 had sustained fractures and 9 required surgery. The distal forearm or wrist were the areas injured most often. Fourteen gymnasts had residual pain, seven had functional limitations, and eight had limited motion in the wrist. Fifteen of the 23 athletes were using a cubital (hyperpronated) grip at the time of injury and 19 were using dowel grips. Among the reasons cited for the injury, 18 gymnasts thought that their grips were either too large, worn, or stretched; 8 said the grips slid up their wrists, and 7 cited technical errors.

The effect of femoral tunnel position and graft tensioning technique on posterior laxity of the posterior cruciate ligament-reconstructed knee.

We report the effects of femoral tunnel position and graft tensioning technique on posterior laxity of the posterior cruciate ligament-reconstructed knee. An isometric femoral tunnel site was located using a specially designed alignment jig. Additional femoral tunnel positions were located 5 mm proximal and distal to the isometric femoral tunnel. With the graft in the proximal femoral tunnel, graft tension decreased as the knee flexed; with the graft in the distal femoral tunnel, graft tension increased as the knee flexed. When the graft was placed in the isometric femoral tunnel, a nearly isometric graft tension was maintained between 0 degrees and 90 degrees of knee flexion. One technique tested was tensioning the graft at 90 degrees of knee flexion while applying an anterior drawer force of 156 N to the tibia. This technique restored statistically normal posterior stability to the posterior cruciate ligament-deficient knee between 0 degrees and 90 degrees for the distal femoral tunnel position, between 0 degrees and 75 degrees for the isometric tunnel position, and between 0 degrees and 45 degrees for the proximal tunnel position. When the graft was tensioned with the knee in full extension and without the application of an anterior drawer force, posterior translation of the reconstructed knee was significantly different from that of the intact knee between 15 degrees and 90 degrees for all femoral tunnel positions.

A comparison of intraarticular morphine and bupivacaine for pain control after outpatient knee arthroscopy. A prospective, randomized, double-blinded study.

To determine the duration of pain relief and efficacy of intraarticular morphine compared with bupivacaine after outpatient knee arthroscopy under local anesthesia, we gave patients one of three postoperative intraarticular injections: 4 mg morphine, 0.25% bupivacaine, or 0.9% saline. Visual analog scale scores and supplemental pain medication use were recorded at 0 to 30 minutes, 2, 4, 6, 8 to 12, and 24 hours after surgery. The score on the visual analog scale at 24 hours was significantly lower in the morphine group than in the bupivacaine or control groups. The cumulative amount of pain medication used was significantly lower in the morphine and bupivacaine groups at 2 to 6 hours after surgery than in the saline control group. The morphine group used the least supplemental pain medication during the 12 to 24 hour interval (P = 0.06). We found that the use of intraarticular morphine or bupivacaine after outpatient knee arthroscopy will decrease the amount of narcotic medication needed for pain relief during the early postoperative period. In addition, morphine provided prolonged pain relief up to 24 hours when compared with bupivacaine or placebo, and the patients in the morphine group tended to take less supplemental pain medication during the first postoperative day.

Iliotibial band tenodesis: a new strategy for attachment.

We investigated the changes in distance between Gerdy's tubercle on the tibia and points on the posterior two thirds of the lateral surface of the lateral femoral condyle and adjacent lateral femoral shaft in 15 cadaveric knees. A three-dimensional digitizer was used to quantify motion of the knee during flexion ranging from full extension to 120 degrees of flexion. Four load states were applied: internal, external, and neutral rotation, and quadriceps muscles loads based on one third of values in the literature for maximal isometric quadriceps muscles moments. The femoral location most isometric to Gerdy's tubercle was found to be strongly influenced by the load state. A 1.0 cm wide iliotibial band tenodesis was modelled by five straight lines arising from Gerdy's tubercle and attaching to a simulated washer at the junction of the lateral femoral condyle and shaft. Using this model and the motion data obtained from the cadavers, we investigated the effects of quadriceps muscles loading and external rotation of the knee on changes in the distances between these tibial and femoral attachments for each of the five lines. A 180 degrees twist modelled into the tenodesis significantly reduced the range of changes in distance (difference between the largest and smallest changes in distance among the lines for a given angle of flexion) for both of these load states. Therefore, a 180 degrees twist in the tenodesis can enhance isometry among the fibers of the tenodesis. This implies that a 180 degrees twist can enhance load sharing among the fibers of the tenodesis and, therefore, enhance the overall strength of the tenodesis.

The effects of arthroscopic partial lateral meniscectomy in an otherwise normal knee: a retrospective review of functional, clinical, and radiographic results.

A retrospective review of patients who underwent arthroscopic partial lateral meniscectomy for lateral meniscus tears in otherwise normal knees was conducted to review the long-term functional, clinical, and radiographic results. Twenty-six patients (27 knees) were evaluated by questionnaire; 20 patients (21 knees) also underwent physical examination and radiographic analysis. Minimum follow-up was 5 years and mean follow-up was 8 years. Patient data were obtained from detailed questionnaires, knee examinations, and radiographs. Excellent or good results decreased from 92% at the time of maximal improvement to 62% at the most recent follow-up: 85% of patients were initially able to return to their preinjury activity level; however, only 48% were able to maintain this level of activity at the most recent follow-up. Seventy-two percent of patients had either one or no Fairbank changes and there was no statistical difference when comparing radiographic criteria in the operated and nonoperated knee. Early results for partial lateral meniscectomy can be quite good; however, significant deterioration of functional results and decreased activity level can occur. Radiographic changes did not correlate with subjective symptoms and functional outcome in our patient population. Our findings suggest that the functional outcome for patients undergoing partial lateral meniscectomy may deteriorate with time and it may be helpful to counsel patients concerning long-term expectations.

Comparison of various icing times in decreasing bone metabolism and blood flow in the knee.

In a previous study we used technetium-99m bone scans to show that cooling a knee for 20 minutes with a standard ice wrap will decrease soft tissue blood flow by a mean of 26%, and skeletal blood flow and metabolism by 19%. The present study examined the effects of shorter and longer icing periods to determine minimum cooling time for a measurable and consistent decrease, and time to produce maximal decrease within a safe period of icing (< 30 minutes). Thirty-eight subjects were studied. An ice wrap was applied to one knee for an assigned time (5, 10, 15, 20, or 25 minutes). Triple-phase bone scans of knees were obtained; mean percentages of decrease in the iced knee for each of the five time groups at each of the three phases of the bone scan were calculated and compared. Mean decreases of 11.1% in soft tissue blood flow, and 5.1% in skeletal metabolism and blood flow were measured at 5 minutes; maximums of 29.5% and 20.9%, respectively, were obtained at 25 minutes. A small but consistent decrease in soft tissue blood flow and skeletal blood flow and metabolism in a knee appear to be obtained with as little as 5 minutes of ice application. This effect is time-dependent and can be enhanced three- to four-fold by increasing the ice application time to 25 minutes.

The effect of thigh and goniometer restraints on the reproducibility of the genucom knee analysis system.

We compared the reproducibility of measurements made with the Genucom knee analysis system using two methods of restraint. The first method was that suggested by the manufacturer and consisted of clamping the thigh to the examination chair with 70 N of vertical force and 110 N of mediolateral force and used a single elastic strap to secure the electrogoniometer cuff to the leg. In the second, or enhanced, method, the vertical and mediolateral clamping forces were each increased to 156 N, and an additional strap was used to secure the cuff to the leg. Tests performed were the anteroposterior stress tests at 20 degrees and 90 degrees of knee flexion, and the varus-valgus stress test, the internal-external rotation stress test, and the medial and lateral pivot shift tests at 20 degrees. Five normal subjects were installed and tested on 6 different days with the manufacturer's suggested securing method and on 12 different days with the enhanced securing method. The enhanced method of restraint resulted in significantly reduced day-to-day variance for all tests performed except the varus-valgus stress test.

Treatment of isolated medial collateral ligament injuries in athletes with early functional rehabilitation. A five-year follow-up study.

A prospective study was designed to provide 5-year followup of the treatment of isolated grade III sprains of the medial collateral ligament with early functional rehabilitation in 35 athletes. After injury, patients were placed in lateral hinged braces to provide valgus support without restricting flexion or extension of the knee. Treatment was initiated with range of motion exercises performed in a whirlpool or swimming pool. Patients were then started on quadriceps setting and leg raises. When 90 degrees of flexion was present, resistive exercises were added. Upon recovery, patients were allowed to return to unrestricted sports. Followup consisted of both questionnaires and physical examination and was graded on the 50-point Hospital for Special Surgery scale. Mean followup was 5.3 years (range, 2.5 to 8); mean Hospital for Special Surgery knee rating score was 45.9 points (range, 41 to 50). These results are comparable with those achieved with surgery or immobilization by earlier investigators. Thus, early functional rehabilitation treatment of complete medial collateral ligament sprains produces results comparable with those achieved with surgery or immobilization while minimizing treatment-related morbidity and allowing more rapid return to sports participation.

An in vitro analysis of patellofemoral contact areas and pressures following procurement of the central one-third patellar tendon.

Patients have complained of pain after the use of the central one-third patellar tendon for reconstruction of the anterior cruciate ligament-deficient knee. This study investigated the effect on patellofemoral contact areas and pressures of harvesting the central 10 mm of the patellar tendon in five cadaveric knees. Isometric quadriceps forces were applied to produce approximately 30% of reported maximum voluntary extension moments at the knee. Using Fuji pressure-sensitive film, measurements were recorded for three states: the normal knee, after the graft removal, and after the tendon was closed. Contact areas and pressures were measured at 20 degrees, 30 degrees, 60 degrees, and 80 degrees of knee flexion in each specimen. Tests of the reproducibility of our methods were performed. Average patellofemoral contact areas for three states ranged from 1.6 cm2 at 20 degrees of knee flexion to 3.0 cm2 at 60 degrees. The average patellofemoral contact pressures ranged from 1.9 MPa at 20 degrees of knee flexion to 3.0 MPa at 30 degrees. At each flexion angle there were no significant differences in average patellar contact area or pressure for the three states (P < 0.05). These results suggest that neither harvesting the central 10 mm of the patellar tendon, nor closing the gap, significantly alters patellofemoral contact area or pressure.

Gait adaptations by patients who have a deficient anterior cruciate ligament.

Sixteen patients who had unilateral deficiency of the anterior cruciate ligament and ten healthy control subjects were analyzed during level walking, jogging, and ascending and descending stairs. Kinematic and kinetic findings for the right and left hips, knees, and ankles of all of the patients and control subjects were recorded during each activity. Substantial differences from normal function were observed for both limbs of the patients during level walking and during jogging. The magnitude of the maximum moment that tended to flex the knee was reduced the most (140 per cent) during level walking. It was reduced less (30 per cent) during jogging, it was not changed while the patient descended stairs, and it was slightly increased while he or she ascended stairs. The reduction in the magnitude of the flexion moment about the knee was interpreted as the patient's effort to reduce or avoid contraction of the quadriceps. Reduction of the flexion moment reduces any contraction of the quadriceps because there must be a mechanical balance between the external moment (due to body weight and the weight and inertia of the segment of the limb) that tends to flex the knee and an internal moment (generated by contraction of the quadriceps) that tends to extend the knee. This so-called quadriceps-avoidance gait was related to the angle of flexion of the knee when the maximum flexion moment occurred during each activity. This angle of flexion was 20 degrees during walking, 40 degrees during jogging, and approximately 60 degrees during stair-climbing.(ABSTRACT TRUNCATED AT 250 WORDS)