The role of the popliteofibular ligament and the tendon of popliteus in providing stability in the human knee.

Techniques for the selective cutting of ligaments in cadaver knees defined the static contributions of the posterolateral structures to external rotation, varus rotation and posterior tibial translation from 0 degrees to 120 degrees of flexion under defined loading conditions. Sectioning of the popliteofibular ligament (PFL) (group 1) produced no significant changes in the limits of the knee movement studied. Sectioning of the PFL and the popliteus tendon (femoral attachment, group 2) produced an increase of only 5 degrees to 6 degrees in external rotation from flexion of 30 degrees to 120 degrees (p < 0.001). Even when other ligaments were sectioned first (group 3), the maximum effect of the PFL was negligible. Our findings show that the popliteus muscle-tendon-ligament complex, lateral collateral ligament, and posterolateral capsular structures function as a unit. No individual structure alone is the primary restraint for the movements studied. Operative reconstruction should address all of the posterolateral structures, since restoration of only a portion may result in residual instability.

The effects of graft width and graft laxity on the outcome of caprine anterior cruciate ligament reconstruction.

We studied how initial graft size and initial graft laxity affected the biomechanics of anterior cruciate ligament (ACL) reconstruction at six months. Sixteen goats had bilateral reconstructions staged eight weeks apart. Autografts 4 and 7 mm wide were taken from the central patellar tendon (PT). Lax grafts were created by adding 4 mm slack to the graft before fixing. We reconstructed each joint using a combination of width and laxity treatments. Both factors were changed for the contralateral joint and all combinations appeared with equal frequency. At six months we measured the joint extension limit, anterior-posterior (AP) translation, and osteoarthritic changes. The grafts were then tested to failure to determine their mechanical properties. After six months the difference in initial treatments had disappeared: there was no difference in graft cross-section due to the different initial widths and there was no difference in joint AP translation due to the initial graft laxity. We did observe that wide grafts were associated with a block to extension, decreased joint AP translation, and increased articular cartilage damage and osteophyte formation. While AP translation was reduced, it was correlated with decreased extension, possibly indicating an increase in scar tissue formation rather than a more functional graft. Neither graft width nor graft laxity produced differences in any graft mechanical properties. This suggests that the use of larger grafts to prevent increased AP translation has undesirable complications. Ultimately, we conclude that neither of these surgical treatments strongly affects the biomechanical result of caprine ACL reconstruction.

Revision anterior cruciate surgery with use of bone-patellar tendon-bone autogenous grafts.

BACKGROUND: A prospective study was done to determine the functional results, patient satisfaction, and graft failure rate after fifty-seven consecutive revision replacements of the anterior cruciate ligament with use of a bone-patellar tendon-bone autogenous graft. METHODS: Fifty-four patients (fifty-five operations) were followed in this study. Concurrent operative procedures were performed during the revision procedure in thirty-seven knees (67%). These procedures included repair of a meniscal tear in twenty knees (36%) and reconstruction of deficient posterolateral or medial ligament structures in seventeen knees (31%). Nine knees (16%) had a high tibial osteotomy to correct varus malalignment before the revision operation. The results were evaluated with the Cincinnati Knee Rating System. RESULTS: There were significant improvements in the scores for pain (p < 0.0001), activities of daily living (p < 0.01), sports participation (p < 0.001), patient satisfaction (p < 0.0001), and overall rating of the knee (p < 0.0001). Thirty-three (60%) of the replaced ligaments were functional, nine (16%) were partially functional, and thirteen (24%) had failed. CONCLUSIONS: Many knees (93%) had compounding problems, including articular cartilage damage, prior meniscectomy, loss of secondary ligament restraints, varus malalignment, and concomitant ligament replacement or meniscal repair. Therefore, the results were generally less favorable than those following primary operations. The rate of graft failure was three times higher than our previously reported failure rate after primary replacements of the anterior cruciate ligament with a bone-patellar tendon-bone autogenous graft. Even so, symptoms and functional limitations with regard to daily and sports activities were found to have decreased and patient satisfaction improved. We advocate correction of varus malalignment prior to anterior cruciate procedures. Associated posterolateral ligament deficiencies should be surgically corrected during anterior cruciate procedures to prevent excessive loading on the graft from abnormal lateral tibiofemoral joint opening. Meniscal tears, including complex tears that extend into the avascular zone, can be concurrently repaired successfully during the revision.

Two-bundle posterior cruciate ligament reconstruction. An in vitro analysis of graft placement and tension.

This study had two purposes: first, to determine how femoral attachment location affects the load sharing between the two bundles of a Y-type posterior cruciate ligament reconstruction, and second, to determine how the bundles, separately and in combination, control posterior tibial translation throughout the full range of knee flexion. One and two-bundle reconstructions were performed in 12 cadaveric knees. The one-bundle reconstructions were attached within the femoral posterior cruciate ligament footprint at one of three locations, high and shallow (S1), mid and shallow (S2), or mid and deep (D). The two-bundle reconstructions comprised an S1 bundle with either an S2 or a D bundle. Posterior translation and bundle tension were measured as the knee was flexed from full extension to 1,200 of flexion while a posterior force of either 50 or 100 N was applied to the proximal tibia. The shallow one-bundle reconstruction restored posterior translation to within 2 mm of that of the intact knee over the entire range of knee flexion. The deep reconstruction did not control abnormal posterior translation above 45 degrees. The tension in the shallow bundles increased with knee flexion, and the deep bundle tension remained nearly constant throughout knee flexion. Both two-bundle reconstructions controlled posterior translation, but with different load-sharing characteristics. The S1-S2 configuration resisted posterior tibial translation as both bundles became taut in flexion. In contrast, the S1-D configuration resisted posterior translation in a reciprocal fashion with the D bundle tension being the greatest in extension and the S1 bundle tension being the greatest tension in flexion.

Arthroscopic repair of meniscus tears extending into the avascular zone with or without anterior cruciate ligament reconstruction in patients 40 years of age and older.

PURPOSE: The purpose of this study was to prospectively determine the outcome of meniscal repairs for tears that extended into the central one-third zone of the meniscus, or had a rim width of 4 mm or greater, in a case series of patients 40 years of age and older. TYPE OF STUDY: Prospective case series. MATERIALS AND METHODS: Thirty meniscal repairs in 29 patients were evaluated by a comprehensive examination (28 repairs) a mean of 34 months postoperatively, by follow-up arthroscopy (6 repairs) a mean of 24 months postoperatively, or both. The mean age of the patients at the time of the meniscal repair was 45 years (range, 40 to 58 years). Twenty-one patients (72%) also had ruptures of the anterior cruciate ligament, which were reconstructed at the time of the meniscal repair with bone-patellar tendon-bone autografts (16 patients) or allografts (5 patients). The Cincinnati Knee Rating System was used to rate symptoms, functional limitations with sports and daily activities, patient perception of the knee condition, and sports and occupational rating levels. RESULTS: At a mean of 33 months postoperatively, 26 meniscal repairs (87%) were asymptomatic for tibiofemoral joint symptoms and had not required subsequent surgery. Three repairs failed to heal, requiring partial meniscectomy, and 1 knee with tibiofemoral symptoms related to the repair was treated conservatively. There was no significant effect of the side of the meniscal repair, chronicity of injury, or condition of the articular cartilage on the presence of tibiofemoral symptoms or meniscal resection. Concomitant anterior cruciate ligament reconstruction appeared to increase the rate of asymptomatic meniscal repairs. The patient rating of overall knee condition was normal/very good in 76%, good in 12%, and fair/poor in 12%. CONCLUSIONS: In athletically active patients, we recommend the preservation of meniscal tissue wherever possible regardless of age, basing indications for the procedure on current and future activity levels.

Prevention of permanent arthrofibrosis after anterior cruciate ligament reconstruction alone or combined with associated procedures: a prospective study in 443 knees.

We prospectively determined the effectiveness of an immediate knee motion and early intervention program to prevent permanent motion limitations in a consecutive series of patients who had anterior cruciate ligament autogenous patellar tendon reconstruction for isolated rupture (219 knees) or combined with other procedures (224 knees). The subjects were placed into either a progressive or delayed rehabilitation program and were followed for at least 12 months postoperatively. At follow-up a normal range of motion (0 degrees to at least 135 degrees) was found in 436 knees (98%), and mild losses of extension (-5 degrees) were found in 7 knees. Twenty-three knees (5%) required interventions; 9 had extension casts, 9 had gentle manipulations under anesthesia, 3 had arthroscopic debridements, and 2 had continuous epidural anesthetic and inpatient therapy. All of these 23 knees regained full motion. The 7 patients with mild losses of extension had refused treatment intervention. The 0% incidence rate of permanent arthrofibrosis, and 0.7% reoperation rate for knee motion limitations, demonstrated the effectiveness of our program.

High tibial osteotomy and ligament reconstruction for varus angulated anterior cruciate ligament-deficient knees.

In a consecutive series, we treated 41 young patients who had anterior cruciate ligament deficiency, lower limb varus angulation, and varying amounts of posterolateral ligament deficiency. Seventy-three percent of the patients (N = 30) had lost the medial meniscus and 63% (N = 26) had marked articular cartilage damage in the medial compartment. All patients were treated with high tibial osteotomy and, in the majority (N = 34), anterior cruciate ligament reconstruction a mean of 8 months later. Posterolateral reconstructions were also required in 18 knees. A 100% follow-up was obtained at a mean of 4.5 years after osteotomy. Gait analysis testing was done in 17 knees before and after osteotomy. At follow-up, a reduction in pain was found in 71% (29 knees); elimination of giving way, in 85% (35 knees); and resumption of light recreational activities without symptoms, in 66% (27 knees). The patient rating of the knee condition was normal or very good in 37% (15 knees) and good in 34% (14 knees). The mean Cincinnati Knee Rating Score significantly improved from 63 to 82 points. The mean adduction moment, 35% higher than controls preoperatively, significantly decreased to below normal values postoperatively. Correction of varus alignment was maintained in 33 knees (80%). We recommend osteotomy in addition to ligament reconstructive procedures in these knees with complex injury patterns.

The effect of neuromuscular training on the incidence of knee injury in female athletes. A prospective study.

To prospectively evaluate the effect of neuromuscular training on the incidence of knee injury in female athletes, we monitored two groups of female athletes, one trained before sports participation and the other not trained, and a group of untrained male athletes throughout the high school soccer, volleyball, and basketball seasons. Weekly reports included the number of practice and competition exposures and mechanism of injury. There were 14 serious knee injuries in the 1263 athletes tracked through the study. Ten of 463 untrained female athletes sustained serious knee injuries (8 noncontact), 2 of 366 trained female athletes sustained serious knee injuries (0 noncontact), and 2 of 434 male athletes sustained serious knee injuries (1 noncontact). The knee injury incidence per 1000 athlete-exposures was 0.43 in untrained female athletes, 0.12 in trained female athletes, and 0.09 in male athletes (P = 0.02, chi-square analysis). Untrained female athletes had a 3.6 times higher incidence of knee injury than trained female athletes (P = 0.05) and 4.8 times higher than male athletes (P = 0.03). The incidence of knee injury in trained female athletes was not significantly different from that in untrained male athletes (P = 0.86). The difference in the incidence of noncontact injuries between the female groups was also significant (P = 0.01). This prospective study demonstrated a decreased incidence of knee injury in female athletes after a specific plyometric training program.

Assessment of sports participation levels following knee injuries.

Although there are many published instruments designed to determine outcome following the treatment of knee injuries, only a few incorporate specific assessments of sports activity level and participation into the evaluation. This article reviews 3 of the most commonly used sports activity outcome instruments: the scales devised by Tegner and Lysholm, the Hospital for Special Surgery and the International Knee Documentation Committee. Problems and potential study biases that can arise with improper questionnaire design and data reduction techniques are reviewed, and recommendations are made to correct these problems. The problems identified include: (i) the failure to precisely define sports activity levels according to a specific sport and intensity of participation; (ii) the failure to sort populations according to overall intensity of athletic participation both before and after treatment; (iii) the failure to detect and sort from the population patients who return to sports and experience significant symptoms; (iv) the combination of work and sports activities into the same scale; and (v) the failure to detect alterations in sports participation caused by changes in lifestyle or non-knee-related factors. We have developed a sports assessment instrument, the Cincinnati Sports Activity Scale (CSAS). The methodology used to create this scale, its use in the assessment of return to or change in sports activities, and the assessment of specific functions of daily and sports activities, are briefly reviewed. The CSAS is based on 2 criteria: (i) the frequency of participation; and (ii) the general types of forces experienced by the lower extremity during the sport. The assessment of change in sports activities accounts for modifications in lifestyle and can also detect patients who have returned to sports but are experiencing significant symptoms and problems. Examples of data reduction and reporting are provided to represent practical situations from a prior investigation.

Rigorous statistical reliability, validity, and responsiveness testing of the Cincinnati knee rating system in 350 subjects with uninjured, injured, or anterior cruciate ligament-reconstructed knees.

Although many instruments are used to assess outcome after knee ligament reconstruction, their reliability, validity, and responsiveness have not been adequately proven. Our purpose was to assess these statistical measures in a commonly used instrument, the Cincinnati Knee Rating System. Reliability was determined from the responses of 100 subjects who completed the instrument twice, a mean of 7 days apart. Validity and responsiveness were assessed from 250 patients observed for at least 2 years after autogenous ACL reconstruction. Questionnaire items included symptoms, functional limitations with sports and daily activities, patient perception of the knee condition, and sports- and occupational-activity levels. The items demonstrated high test-retest reliability, supporting their use in evaluating groups of patients between two different treatment periods (all intraclass correlation coefficients > 0.70). In addition, the questionnaire demonstrated good content validity, construct validity, and item-discriminant validity. For the overall rating score, no "floor effects" (worst score possible) were found before or after surgery. No "ceiling effects" (best score possible) were found before surgery, and, at follow-up, these effects were calculated in only 22 patients (9%). The questions were found to be highly responsive to detecting changes between evaluations. The data demonstrated that this rating system has acceptable reliability, validity, and responsiveness for use in outcome studies after knee ligament reconstruction.

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%.

Physical and arthroscopic examination techniques of the patellofemoral joint.

A systematic approach to the clinical history, physical, and arthroscopic examination of patellofemoral disorders will lead to improved diagnostic accuracy and clinical treatment success. We review important aspects of physical and arthroscopic examination of patellofemoral disorders Basic and advanced physical examination techniques are presented, and their clinical significance is reviewed. Arthroscopic examination of the patellofemoral joint is used as an adjunct to physical examination to evaluate chondral lesions of the patella and femoral sulcus and to visualize patella tracking. Techniques to assess patellar tracking and the integrity of patellar restraints and to grade chondral lesions are outlined. Utilization of these techniques will improve clinical studies on the treatment of patellofemoral disorders.

Decrease in knee joint pain and increase in function in patients with medial compartment arthrosis: a prospective analysis of valgus bracing.

We studied a brace designed to decrease loads on the medial tibiofemoral compartment in knees with chronic pain and arthrosis to determine if pain symptoms decreased, function improved, and dynamic gait characteristics altered during walking. Eighteen patients with symptomatic medial compartment arthrosis were fitted with a commercially available brace. All were evaluated after an average of 9 weeks of brace wear, and 13 patients were evaluated after 1 year of brace wear. The Cincinnati Knee Rating System and additional pain scales were used to analyze symptoms and functional limitations. Nine subjects underwent a dynamic gait analysis and were compared with a control group of 11 normal subjects matched for age and walking speed. The brace was worn an average of 7 hours a day, 5 days a week. Following 9 weeks of brace wear, statistically significant improvements were found for all pain parameters, and these improvements continued at the 1 year evaluation. Before brace wear, 78% had pain with activities of daily living, but after the first evaluation, only 39% continued to have such pain, and at the second evaluation, only 31% were so affected. Before brace wear, patients had a walking tolerance of 51 minutes prior to the onset of pain symptoms. At the first evaluation, patients could walk 138 minutes without pain, and after 1 year, they could walk 107 minutes without pain. Before brace wear, 78% rated their overall knee condition as fair or poor whereas at the first evaluation, only 33% continued to provide this rating. No differences were found in the dynamic gait parameters measured with and without the brace. While this brace did not provide the dramatic improvements in symptoms, function, and patient satisfaction obtainable after high tibial osteotomy, it did help the majority of patients. If the goal of brace use is to buy a short amount of time for patients who cannot undergo or wish to avoid osteotomy or knee arthroplasty, then bracing appears to offer a reasonable alternative for short-term pain relief and improved function.

Arthroscopic repair of meniscal tears that extend into the avascular zone. A review of 198 single and complex tears.

We assessed the results of 198 meniscal tears that had a major segment in the central avascular region repaired with an arthroscopically assisted inside-out technique. There were 177 patients whose mean age was 28 years. Eighty-two percent were injured during sports, and 71% also required anterior cruciate ligament reconstruction. The menisci were evaluated by clinical examination (180 repairs) a mean of 42 months postoperatively, by follow-up arthroscopic evaluation (91 repairs) a mean of 18 months postoperatively, or both. At followup, 159 (80%) of the 198 tears were asymptomatic for tibiofemoral joint symptoms, and 39 (20%) required repeat arthroscopic surgery for these symptoms. Of the 91 repairs evaluated arthroscopically, 23 (25%) were classified as healed, 35 (38%) as partially healed, and 33 (36%) as failed. We recommend repair of meniscal tears that extend into the avascular region for select patients, including those in their 20s and 30s and highly competitive athletes. This study's reoperation rate of 20% should not be interpreted as the rate of meniscal healing, but as the incidence of tibiofemoral joint symptoms. Even though this is a higher rate than that reported for the repair of peripheral meniscal tears, we believe the benefits of a potentially functional meniscus outweigh the risks of reoperation.

Reconstruction of the anterior and posterior cruciate ligaments after knee dislocation. Use of early protected postoperative motion to decrease arthrofibrosis.

We report a critical rating of results for 11 patients with bicruciate ligament reconstructions and immediate protected knee motion after knee dislocations (seven acute and four chronic). Six patients had concurrent repair or reconstruction of medial ligamentous structures, and six had reconstruction of the lateral and posterolateral ligaments. All patients returned for followup at a mean of 4.8 years postoperatively. Follow-up arthrometric testing at 20 degrees of flexion showed 10 knees had less than 3 mm of increased total anterior-posterior displacement and 1 knee had 7 mm of increase. At 70 degrees of flexion, 9 knees had less than 3 mm of increased displacement and 2 knees had more than 6 mm of increase. The failure rates were as follows: 18% of posterior cruciate ligament reconstructions (2 of 11), 9% of anterior cruciate ligament reconstructions (1 of 11), 17% of lateral and posterolateral procedures, and 0% of medial collateral ligament procedures. At followup, five of the seven patients with acute injuries had no limitations with daily or sports activities. Three of the four patients with chronic ruptures were asymptomatic with daily activities, but only one was asymptomatic with light sports. Five patients (all acute injuries) required treatment for knee motion limitations. Nine patients had full range of motion at followup. We concluded that simultaneous bicruciate ligament reconstructions, performed with associated medial or lateral procedures, are warranted to restore function to all ligament structures. Even though immediate motion was used, several patients required early manipulation or arthroscopic debridement, which restored full motion and prevented permanent arthrofibrosis.

Anterior cruciate ligament reconstruction with autogenous patellar tendon graft in patients with articular cartilage damage.

To test if anterior cruciate ligament reconstruction with autogenous patellar tendon can alleviate symptoms and functional limitations and increase activity levels in patients with advanced articular cartilage damage, we looked at 53 patients with arthroscopically documented cartilage damage. In this group, a mean of 7.5 years had elapsed between the original injury and the reconstruction, and 90 prior operative procedures had been done. Postoperatively, all patients had immediate motion and early functional rehabilitation. The results were assessed with the Cincinnati Knee Rating System. At followup (mean, 27 months), significant improvements were found for pain, swelling, giving way, functional limitations with daily and sports activities, and the overall rating score. Forty-two patients (79%) had returned to some type of athletic activity. Only three patients (6%) had failed results. In the patients' own ratings of the overall knee condition, 8 of 51 (16%) rated their knees as normal, 28 (55%) as very good, 7 (14%) as good, 5 (10%) as fair, and 3 (6%) as poor. We concluded that the majority of patients benefited from the arthroscopically assisted anterior cruciate ligament reconstruction because it decreased episodes of giving way with daily activities and increased activity without aggravating the preexisting arthrosis.