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PubMedDate not supplied

Anterior cruciate ligament function after tibial eminence fracture in skeletally mature patients.

We compared anterior cruciate ligament function in skeletally mature patients after treatment of tibial eminence fractures with that of patients in two other groups: patients who had anterior cruciate ligament deficiency and patients who had undergone anterior cruciate ligament reconstruction using bone-patellar tendon-bone autografts. The Lysholm questionnaire was used to evaluate symptoms and KT-1000 arthrometry was used to determine objective knee laxity at an average follow-up of 5.2 years. Knee joint proprioception was assessed with a new method designed to test joint position sense. The Lysholm score for the tibial eminence group was 94 +/- 7. Only the patients in the anterior cruciate ligament-deficient group demonstrated statistically significantly increased laxity and inferior proprioception when the injured leg was compared with the uninjured leg. Both laxity and proprioception were statistically inferior for the anterior cruciate ligament-deficient group when compared with both the treated tibial eminence fracture group and the anterior cruciate ligament-reconstructed group. No statistically significant difference was observed between the anterior cruciate ligament-reconstructed and treated tibial eminence fracture groups. Correlation was observed between laxity and proprioception when all patients were analyzed. The results demonstrate that appropriate treatment of tibial eminence fractures restores stability and proprioception to the knee.

Adolescent↗
PubMedDate not supplied

Radiofrequency electrothermal shrinkage of the anterior cruciate ligament.

The efficacy of electrothermal collagen shrinkage in the treatment of patients with anterior cruciate ligament laxity was evaluated. Eighteen patients who had continuity of the anterior cruciate ligament but had symptomatic laxity were treated with arthroscopic electrothermal shrinkage of the anterior cruciate ligament using a monopolar radiofrequency probe. The mean length of follow-up in patients whose stability was maintained was 20.5 months. Seven of the patients had undergone previous reconstruction, four with patellar tendon graft and three with quadrupled hamstring tendon graft. Laxity was chronic in nine patients and acute in nine. The KT-1000 arthrometer results at 1 month postoperatively revealed decreased anterior excursion, with an average side-to-side difference of 1.9 mm. However, 11 patients had a failed result at an average 4.0 months. Of the seven patients with successful results, six had native ligaments and had been treated for acute laxity and one had a patellar tendon graft and had been treated for chronic laxity. Even with the short-term follow-up in our study, it is evident that thermal shrinkage using radiofrequency technology has limited application for patients with anterior cruciate ligament laxity. Although it may be useful in treating patients with an acutely injured native anterior cruciate ligament, further study is needed to see if the ligament stretches out over time or is at increased risk of reinjury.

Adolescent↗
PubMedDate not supplied

The effect of injury to the posterolateral structures of the knee on force in a posterior cruciate ligament graft: a biomechanical study.

To determine whether untreated grade 3 posterolateral knee injuries contribute to a significant increase in force on a posterior cruciate ligament reconstruction graft, we measured the force on the graft during joint loading of a posterior cruciate ligament-reconstructed knee with otherwise intact structures and then selectively cut the popliteofibular ligament, popliteus tendon, and the fibular collateral ligament. A posterior cruciate ligament reconstruction was performed in eight fresh-frozen cadaveric knees. One end of the graft was fixed to a tensioning jig with a load cell used to measure force in the graft as loads were applied to the knee. The force on the graft was significantly higher with the posterolateral structures cut during varus loading at 30 degrees, 60 degrees, and 90 degrees of flexion than it was in the same joint under the same loading conditions but with the posterolateral structures intact. Additionally, coupled loading of posterior drawer force and external tibial torque at 30 degrees, 60 degrees, and 90 degrees significantly increased force on the graft with the posterolateral structures cut. There was no significant increase in force on the graft under any condition with a posterior force, valgus force, or internal and external tibial torque applied alone. A significant increase in force occurs in a posterior cruciate ligament graft in knees with deficient posterolateral knee structures. We recommend that in knees with grade 3 posterolateral injuries and evidence of varus or coupled posterior-external rotation instability the posterolateral structures be repaired or reconstructed at the time of posterior cruciate ligament reconstruction to decrease the chance of later graft failure.

Biomechanical Phenomena↗
PubMedDate not supplied

Three-dimensional tibiofemoral kinematics of the anterior cruciate ligament-deficient and reconstructed knee during walking.

BACKGROUND: It is possible that gait abnormalities may play a role in the pathogenesis of meniscal or chondral injury as well as osteoarthritis of the knee in patients with anterior cruciate ligament deficiency. HYPOTHESIS: The three-dimensional kinematics of anterior cruciate ligament-deficient knees are changed even during low-stress activities, such as walking, but can be restored by reconstruction. STUDY DESIGN: Case control study. METHODS: Using a three-dimensional optoelectronic gait analysis system, we examined 13 patients with anterior cruciate ligament-deficient knees, 21 patients with anterior cruciate ligament-reconstructed knees, and 10 control subjects with uninjured knees during walking. RESULTS: Normal patterns of knee flexion-extension, abduction-adduction, and internal-external rotation during the gait cycle were maintained by all subjects. A significant difference in tibial rotation angle during the initial swing phase was found in anterior cruciate ligament-deficient knees compared with reconstructed and control knees. The patients with anterior cruciate ligament-deficient knees rotated the tibia internally during the initial swing phase, whereas the others rotated externally. CONCLUSIONS: Patients with anterior cruciate ligament-deficient knees experienced repeated episodes of rotational instability during walking, whereas patients with reconstruction experienced tibial rotation that is closer to normal. CLINICAL RELEVANCE: Repeated episodes of knee rotational instability may play a role in the development of pathologic knee conditions.

Adult↗
PubMedDate not supplied

The soleus muscle acts as an agonist for the anterior cruciate ligament. An in vitro experimental study.

BACKGROUND: Although the quadriceps muscles are known antagonists for the anterior cruciate ligament and the hamstring muscles are known agonists, the influence of the calf muscles on knee stability is not well understood. HYPOTHESIS: The soleus muscle acts as an anterior cruciate ligament agonist and the gastrocnemius muscle acts as an anterior cruciate ligament antagonist. STUDY DESIGN: Controlled laboratory study. METHODS: Six cadaveric knees were tested with individual and combined activation of the gastrocnemius and soleus muscles to determine the influence of simulated muscle contraction on tibiofemoral motion. RESULTS: At all flexion angles, applying the soleus muscle force tended to translate the tibia posteriorly, whereas applying the gastrocnemius muscle force tended to translate the tibia anteriorly. Applying the soleus and gastrocnemius muscle forces together also tended to translate the tibia anteriorly. The average anterior and posterior tibial translations were greatest at 50 degrees of flexion. CONCLUSIONS: The soleus muscle is capable of acting as an agonist for the anterior cruciate ligament and the gastrocnemius muscle can act as an antagonist. CLINICAL RELEVANCE: A better understanding of the agonistic behavior of the soleus muscle on the anterior cruciate ligament may lead to the development of training and rehabilitation strategies that could reduce the incidence of injury and improve function in both patients with anterior cruciate ligament deficiency and patients who have undergone anterior cruciate ligament reconstruction.

Aged↗
PubMedDate not supplied

Reconstruction of the coracoclavicular ligaments with tendon grafts: a comparative biomechanical study.

BACKGROUND: Numerous surgical techniques have been described to address injuries to the coracoclavicular ligaments. PURPOSE: To compare the biomechanical properties of tendon graft reconstructions with those of the native coracoclavicular ligaments and various other repair methods. STUDY DESIGN: Controlled laboratory study. METHODS: Eleven fresh-frozen human cadaveric shoulders were tensile tested to failure to compare the biomechanical properties of the native coracoclavicular ligaments, coracoacromial ligament transfer, No. 5 Mersilene suture repair, 5-mm Mersilene tape repair, and tendon graft reconstructions with gracilis, semitendinosus, and long toe extensor tendons. RESULTS: Reconstructions with semitendinosus, gracilis, or long toe extensor tendon grafts were found to have superior initial biomechanical properties compared with coracoacromial ligament transfer; failure strengths were as strong as those of the native coracoclavicular ligaments. Failure of the tendon grafts occurred through the midsubstance of the tendon graft, not at the fixation site. CONCLUSIONS: Tendon graft reconstruction may be an alternative to coracoacromial ligament transfer and may provide a permanent biologic reconstruction with superior initial biomechanical properties, including that of tensile strength. CLINICAL RELEVANCE: Use of tendon graft reconstruction may limit the need for postoperative immobilization and lead to an accelerated rehabilitation program.

Adult↗
PubMedDate not supplied

The effect of femoral tunnel position on graft forces during inlay posterior cruciate ligament reconstruction.

BACKGROUND: The femoral tunnel may be positioned centrally or eccentrically within the posterior cruciate ligament footprint during a single-bundle posterior cruciate ligament reconstruction. HYPOTHESIS: After reconstruction, graft forces are significantly different from those of the native posterior cruciate ligament and are affected by the position of the femoral tunnel. STUDY DESIGN: Controlled laboratory study. METHODS: The resultant force in the native posterior cruciate ligament was measured in nine cadaveric knees as the knee was flexed from -5 degrees to 120 degrees of flexion. Posterior cruciate ligament reconstruction was performed with the femoral side of the graft positioned centrally and then offset 5 mm eccentric to the central position. RESULTS: Mean graft forces were not significantly different between eccentric and central tunnel positions during passive knee extension between 120 degrees and 0 degrees of flexion; at 5 degrees of hyperextension, the eccentric position generated significantly lower graft forces. For both reconstruction techniques, mean graft forces were significantly higher than those for the native posterior cruciate ligament beyond approximately 90 degrees of flexion, for 5 N.m internal and external tibial torque; 5 N.m varus and valgus moment. CONCLUSIONS: Graft force reductions achieved with the eccentric femoral position appear to be relatively small compared with the forces expected during rehabilitation and activities of daily living. CLINICAL RELEVANCE: After posterior cruciate ligament graft reconstruction, rehabilitation activities that load the knee at high degrees of flexion should be avoided to limit excessive forces on the maturing graft.

Adult↗
PubMedDate not supplied

Risk factors associated with noncontact injury of the anterior cruciate ligament: a prospective four-year evaluation of 859 West Point cadets.

BACKGROUND: The causes of noncontact anterior cruciate ligament injury remain an enigma. PURPOSE: To prospectively evaluate risk factors for noncontact anterior cruciate ligament injuries in a large population of young athletic people. STUDY DESIGN: Prospective cohort study. METHODS: In 1995, 1198 new United States Military Academy cadets underwent detailed testing and many parameters were documented. During their 4-year tenure, all anterior cruciate ligament injuries that occurred were identified. Statistical analyses were used to identify the factors that may have predisposed the cadets to noncontact anterior cruciate ligament injuries. RESULTS: Among the 895 cadets who completed the entire 4-year study, there were 24 noncontact anterior cruciate ligament tears (16 in men, 8 in women). Significant risk factors included small femoral notch width, generalized joint laxity, and, in women, higher than normal body mass index and KT-2000 arthrometer values that were 1 standard deviation or more above the mean. The presence of more than one of these risk factors greatly increased the relative risk of injury. All female cadets who had some combination of risk factors sustained noncontact anterior cruciate ligament injuries, indicating that some combinations of factors are especially perilous to the female knee. CONCLUSION: Several risk factors may predispose young athletes to noncontact anterior cruciate ligament injury.

Adolescent↗
PubMedDate not supplied

The effect of wedged insoles on the lateral thrust of anterior cruciate ligament-insufficient knees.

BACKGROUND: Patients with untreated anterior cruciate ligament insufficiency often develop osteoarthritis. In Japan, laterally or medially elevated insoles have been widely used for the relief of symptoms associated with unicompartmental osteoarthritis of the knee. HYPOTHESIS: The use of a valgus wedge in the shoe of a patient with anterior cruciate ligament insufficiency will decrease lateral thrust. STUDY DESIGN: Controlled laboratory study. METHODS: An accelerometer was used to measure thrust force in 60 control knees and 35 knees with anterior cruciate ligament insufficiency. The sensor was attached to the affected and the control anterior tibial tubercles to record motion in the medial-lateral and perpendicular directions. The lateral thrust immediately after heel strike was measured continuously by a telemeter under stabilized walking conditions. Measurements were made both with and without wedged insoles. RESULTS: When compared with the control knee, the peak value of lateral acceleration immediately after heel strike was significantly greater in the anterior cruciate ligament-insufficient knees. However, lateral thrust decreased significantly in the anterior cruciate ligament-insufficient knees when a wedged insole was used. CONCLUSIONS: Use of an insole resulted in a significant decrease in lateral thrust, even in anterior cruciate ligament-insufficient knees. CLINICAL RELEVANCE: Use of an insole is one possible prophylaxis for osteoarthritis for an anterior cruciate ligament-insufficient knee.

Acceleration↗
PubMed2004

Knee stability and graft function after anterior cruciate ligament reconstruction: a comparison of a lateral and an anatomical femoral tunnel placement.

BACKGROUND: Locations of femoral tunnels for anterior cruciate ligament replacement grafts remain a subject of debate. HYPOTHESIS: A lateral femoral tunnel placed at the insertion of the posterolateral bundle of the anterior cruciate ligament can restore knee function comparably to anatomical femoral tunnel placement. STUDY DESIGN: Controlled laboratory study. METHODS: Ten cadaveric knees were subjected to the following external loading conditions: (1) a 134-N anterior tibial load and (2) combined rotatory loads of 10-N.m valgus and 5-N.m internal tibial torques. Data on resulting knee kinematics and in situ force of the intact anterior cruciate ligament and anterior cruciate ligament graft were collected using a robotic/universal force-moment sensor testing system for (1) intact, (2) anterior cruciate ligament-deficient, (3) anatomical double-bundle reconstructed, and (4) laterally placed single-bundle reconstructed knees. RESULTS: In response to anterior tibial load, anterior tibial translation and in situ force in the graft were not significantly different between the 2 reconstructions except at high knee flexion. For example, at 90 degrees of knee flexion, anterior tibial translation was 6.1 +/- 2.3 mm for anatomical double-bundle reconstruction and 7.6 +/- 2.6 mm for laterally placed single-bundle reconstruction (P < .05). In response to rotatory loads, there were no significant differences between the 2 reconstruction procedures (4.8 +/- 2.4 mm vs 4.8 +/- 3.0 mm in anterior tibial translation at 15 degrees of knee flexion, P > .05). CONCLUSION: Lateral tunnel placement can restore rotatory and anterior knee stability similarly to an anatomical reconstruction when the knee is near extension. However, the same is not true when the knee is at high flexion angles. CLINICAL RELEVANCE: To reproduce the complex function of the anterior cruciate ligament, reproducing both bundles of the anterior cruciate ligament may be necessary.

Adult↗
PubMed2004

The effect of posterior cruciate ligament deficiency on knee kinematics.

BACKGROUND: Alteration of the kinematics of the PCL-deficient knee might be a factor in producing the articular damage. Very little is known about the in vivo weightbearing kinematics of the PCL-deficient knee. HYPOTHESIS: Isolated rupture of the posterior cruciate ligament alters knee kinematics, predisposing the patient to development of early osteoarthritis. STUDY DESIGN: Case series. METHODS: Tibiofemoral motion was assessed using open-access magnetic resonance imaging, weightbearing in a squat, through the arc of flexion from 0 degrees to 90 degrees in 6 patients with isolated rupture of the posterior cruciate ligament in one knee and a normal contralateral knee. Passive sagittal laxity was assessed by performing the posterior and anterior drawer tests while the knees were scanned, again using the same magnetic resonance imaging scanner. The tibiofemoral positions during this stress magnetic resonance imaging examination were measured from midmedial and midlateral sagittal images of the knees. RESULTS: Rupture of the posterior cruciate ligament leads to an increase in passive sagittal laxity in the medial compartment of the knee (P < .006). In the weightbearing scans, posterior cruciate ligament rupture alters the kinematics of the knee with persistent posterior subluxation of the medial tibia so that the femoral condyle rides up the anterior upslope of the medial tibial plateau. This fixed subluxation was observed throughout the extension-flexion arc and was statistically significant at all flexion angles (P < .018 at 0 degrees , P < .013 at 20 degrees , P < .014 at 45 degrees , P < .004 at 90 degrees ). The kinematics of the lateral compartment were not altered by posterior cruciate ligament rupture. The posterior drawer test showed increased laxity in the medial compartment. CONCLUSION: Posterior cruciate ligament rupture alters the kinematics of the medial compartment of the knee, resulting in "fixed" anterior subluxation of the medial femoral condyle (posterior subluxation of the medial tibial plateau). This study helps to explain the observation of increased incidence of osteoarthritis in the medial compartment, and specifically the femoral condyle, in posterior cruciate ligament-deficient knees.

Adult↗
PubMed2005

Effects of administration of exogenous growth factors on biomechanical properties of the elongation-type anterior cruciate ligament injury with partial laceration.

BACKGROUND: No studies have been conducted to clarify the in vivo effect of growth factor application on healing in the injured anterior cruciate ligament. HYPOTHESIS: Administration of exogenous growth factors significantly increases the structural properties of the injured anterior cruciate ligament. STUDY DESIGN: Controlled laboratory study. METHODS: Thirty-six rabbits were randomly divided into 4 groups of 9 animals each after an overstretched injury was made in the right anterior cruciate ligament. In group 1, no treatment was applied around the injured anterior cruciate ligament. In group 2, 0.2 mL fibrin sealant was applied around it. In group 3, 4 ng transforming growth factor-beta1 mixed with 0.2 mL fibrin sealant was applied. In group 4, 20 microg platelet-derived growth factor-BB mixed with 0.2 mL fibrin sealant was applied. Each rabbit was sacrificed at 12 weeks after the surgery. In addition, 9 knees randomly harvested from all the left knees were used to obtain normal control data. The femur-anterior cruciate ligament-tibia complex specimens were biomechanically and histologically evaluated. RESULTS: Concerning the maximum load and the stiffness, group 3 was significantly greater than groups 1 and 2, whereas there were no significant differences among groups 1, 2, and 4. Groups 1, 2, 3, and 4 were significantly lower than the control group. CONCLUSIONS: The application of 4 ng transforming growth factor-beta1 significantly enhances healing in the injured anterior cruciate ligament. CLINICAL RELEVANCE: Administration of certain growth factors is of value to be studied as one of the future therapeutic options for the overstretched anterior cruciate ligament injury.

Animals↗
PubMed2005

The transverse humeral ligament: a separate anatomical structure or a continuation of the osseous attachment of the rotator cuff?

BACKGROUND: No study to date has isolated the anatomical nature of the transverse humeral ligament and its relationship to the biceps tendon and the anterosuperior portion of the rotator cuff. HYPOTHESIS: There is no separate identifiable transverse humeral ligament, but rather the fibers covering the intertubercular groove are composed of a sling formed by fibers from the subscapularis and supraspinatus tendons. STUDY DESIGN: Descriptive laboratory study. METHODS: A total of 14 shoulder examinations were performed on 7 matched pairs of fresh-frozen cadaveric shoulders. Magnetic resonance imaging scans were performed, followed by gross and microscopic anatomical dissection. RESULTS: In the location of the transverse humeral ligament, magnetic resonance imaging and gross dissection revealed the continuation of superficial fibers of the subscapularis tendon from the tendon body across the intertubercular groove to attach to the greater tuberosity, whereas deeper fibers of the subscapularis tendon inserted on the lesser tuberosity. Longitudinal fibers of the supraspinatus tendon and the coracohumeral ligament were also noted to travel the length of the groove, deep to the other interdigitating fibers but superficial to the biceps tendon. Histologic studies confirmed these gross dissection patterns of fiber attachment and also revealed the absence of elastin fibers, which are more commonly seen in ligamentous structures and are typically absent from tendinous structures. CONCLUSION: There is no identifiable transverse humeral ligament, but rather the fibers covering the intertubercular groove are composed of a sling formed mainly by the fibers of the subscapularis tendon, with contributions from the supraspinatus tendon and the coracohumeral ligament. CLINICAL RELEVANCE: According to our findings, dislocations of the long head of the biceps must disrupt at least the deep fibers of the annular sling created mainly by the subscapularis tendon insertion. This finding provides anatomical support for the findings of a positive biceps tendon subluxation or dislocation and subscapularis tear during glenohumeral arthroscopy with a normal-appearing subscapularis during open surgery or subacromial arthroscopy.

Aged↗
PubMed2005

Effects of knee flexion angles for graft fixation on force distribution in double-bundle anterior cruciate ligament grafts.

BACKGROUND: In double-bundle anterior cruciate ligament reconstruction, overloading either 1 of the 2 grafts should be avoided to decrease the risk of graft failure. HYPOTHESIS: Overloading of the posterolateral graft may occur when it is fixed at 30 degrees of knee flexion because the posterolateral bundle is elongated as the knee approaches extension. STUDY DESIGN: Controlled laboratory study. METHODS: Ten human cadaveric knees were tested at (1) intact, (2) anterior cruciate ligament-deficient, (3) double-bundle anterior cruciate ligament reconstruction with the anteromedial and posterolateral grafts fixed at 60 degrees of flexion and full extension, respectively (fixation 60/FE), and (4) double-bundle anterior cruciate ligament reconstruction with both grafts fixed at 30 degrees of flexion simultaneously (fixation 30/30). Two external loading conditions simulating clinical examinations were used: (1) 134-N anterior tibial load and (2) combined rotatory loads of 10 N x m valgus and 5 N x m internal tibial torques. Data on knee kinematics and in situ forces in the 2 bundles of the intact anterior cruciate ligament and the respective grafts were obtained. RESULTS: In response to 134-N anterior tibial load, knee kinematics and in situ force in the grafts were similar to the intact knee for both fixation protocols. The force in the anteromedial graft for fixation 60/FE was 34% higher, whereas the posterolateral graft for fixation 30/30 was 46% higher, compared with the intact anteromedial and posterolateral bundles, respectively. In response to combined rotatory loads, the posterolateral graft for fixation 30/30 carried 67% higher load than did the intact posterolateral bundle. CONCLUSION: Fixation 30/30 overloaded the posterolateral graft, whereas fixation 60/FE overloaded the anteromedial graft. CLINICAL RELEVANCE: In double-bundle anterior cruciate ligament reconstruction, even though overall forces in the graft are the same as intact anterior cruciate ligament, the force distributions may not be the same as the intact bundles, and overloading of 1 of the 2 grafts may occur.

Adult↗
PubMed2006

The relationship between menstrual cycle phase and anterior cruciate ligament injury: a case-control study of recreational alpine skiers.

BACKGROUND: Female athletes suffer a greater incidence of anterior cruciate ligament tears compared with male athletes when participating in common sports; however, very little is known about the factors that explain this disparity. STUDY DESIGN: Case-control study; Level of evidence, 3. METHODS: Female recreational alpine skiers with an anterior cruciate ligament rupture and age-matched control skiers provided a serum sample and self-reported menstrual history data immediately after injury. Both serum concentrations of progesterone and menstrual history were then used to group subjects into either preovulatory or postovulatory phases of the menstrual cycle. RESULTS: Analysis of serum concentrations of progesterone revealed that alpine skiers in the preovulatory phase of the menstrual cycle were significantly more likely to tear their anterior cruciate ligaments than were skiers in the postovulatory phase (odds ratio, 3.22; 95% confidence interval, 1.09-9.52; P = .027). Analysis of menstrual history data found similar results, but the difference was not statistically significant (odds ratio, 2.38; 95% confidence interval, 0.86-6.54; P = .086). CONCLUSION: The likelihood of sustaining an anterior cruciate ligament injury does not remain constant during the menstrual cycle; instead, the risk of suffering an anterior cruciate ligament disruption is significantly greater during the preovulatory phase of the menstrual cycle compared with the postovulatory phase. CLINICAL RELEVANCE: Phase of menstrual cycle may be one of the risk factors that influence knee ligament injury among female alpine skiers. The findings from this study should be considered in subsequent studies designed to identify persons at risk for anterior cruciate ligament injury and to develop intervention strategies.

Adolescent↗
PubMed2006

Technical errors during medial patellofemoral ligament reconstruction could overload medial patellofemoral cartilage: a computational analysis.

BACKGROUND: The influence of reconstruction of the medial patellofemoral ligament on the patellofemoral force and pressure distributions has not yet been investigated. HYPOTHESIS: Technical errors can cause tension to develop within a reconstructed medial patellofemoral ligament, which will adversely alter the normal patellofemoral force distribution by increasing the load applied to the medial cartilage. STUDY DESIGN: Controlled laboratory study. METHODS: Four computational knee models were used to simulate knee function from 30 degrees to 90 degrees of flexion with (1) an intact medial patellofemoral ligament, (2) an anatomically correct reconstruction using a double hamstring tendon autograft, (3) a 5-mm proximally malpositioned femoral attachment site, (4) a graft that is 3 mm shorter than the intact medial patellofemoral ligament, and (5) combined proximal malpositioning and a short graft. RESULTS: The results were similar for the intact and anatomically reconstructed medial patellofemoral ligament. Proximal malpositioning of the femoral attachment and using a short graft increased the graft tension during flexion, which decreased the lateral force and the lateral tilt moment acting on the patella. When a short graft was combined with proximal malpositioning, the compressive force applied to the medial cartilage at least doubled at low flexion angles, which increased the peak medial pressure by more than 50% at low flexion angles. CONCLUSION: When the medial patellofemoral ligament is reconstructed, small errors in graft length and position can dramatically increase the force and pressure applied to medial patellofemoral cartilage. CLINICAL RELEVANCE: Overloading the medial cartilage after medial patellofemoral ligament reconstruction could lead to degradation, pain, and arthrosis.

Cartilage, Articular↗
PubMedDate not supplied

Secondary reconstruction of anterior cruciate ligament in athletes by using the semitendinosus tendon. Preliminary report of 78 cases.

Secondary reconstruction of the torn anterior cruciate ligament has been accomplished by semitendinosus tenodesis in 78 athletes (average age, 20 years; range, 13 to 45 years old). This series was limited to patients who had isolated tears of the ligament or tears of the anterior cruciate ligament associated with tears of one or both menisci. Meniscectomies were performed in 71 knees and reefing of the posteromedial capsular ligament in 35 knees. After an average of 11 months of follow-up (range, 6 to 29 months postoperatively), 67 (86%) of the patients have obtained significant improvement (0 to 1+ on a scale of 0 to 3+) in anteroposterior and anteromedial rotational instability of the joint. The viability and function of the reconstructed ligament was confirmed by direct visualization in three patients at 12, 25 and 26 months postoperatively. Reefing of the posteromedial capsular ligament appears to increase anteromedial rotation stability. This series will be expanded and the follow-up evaluations will continue over a period of years in an effort to determine whether or not semitendinosus tenodesis is superior to other methods of intraarticular reconstruction for a torn anterior cruciate ligament.

Adolescent↗
PubMedDate not supplied

Disruption of the vastus medialis obliquus with medial knee ligament injuries.

We reviewed the clinical records of 189 consecutive surgically treated acute ligamentous injuries of the medial compartment of the knee to determine the prevalence of disruptions of the vastus medialis obliquus muscle and to document the results of simultaneous repair of the disruption. Forty knees (40 patients) demonstrated a vastus medialis muscle disruption at the time of surgical repair for the medial ligamentous disruption. All were surgically corrected and the sites of tearing were documented. The vastus medialis obliquus muscle was ruptured from the adductor tubercle in 31 (78%) knees. Of these, the tibial collateral ligament was torn from its femoral attachment in 19 (61%) knees and the meniscofemoral portion of the capsular ligament ligament was torn from its femoral attachment in 23 (74%) knees. The vastus medialis obliquus muscle was ruptured from the patella in seven (18%) knees and was ruptured interstitially in nine (23%) knees. Each of the 40 patients returned for objective, subjective, and functional follow-up evaluation (average, 39 months). At follow-up examination, 88% of the 40 knees were rated as good subjectively, 90% objectively, and 93% functionally. A high correlation exists between tears of the vastus medialis obliquus muscle from its femoral attachment and tears of the medial compartment ligaments from their respective femoral attachments. Surgical repair of disruptions of the vastus medialis obliquus muscle at the time of primary repair of injury to the ligaments of the medial compartment of the knee can prevent subsequent disorder of the extensor mechanism and can produce an objectively, subjectively, and functionally stable knee.

Female↗