Knee function after anterior cruciate ligament injury in elite collegiate athletes.

BACKGROUND: Anterior cruciate ligament injuries are common in athletes, but there are few studies of long-term outcomes. HYPOTHESIS: Long-term knee function of anterior cruciate ligament-injured athletes is inferior to that of their uninjured teammates. STUDY DESIGN: Retrospective cohort study. METHODS: Thirty-three Division I-A athletes who had sustained an anterior cruciate ligament injury during their college career completed a series of questionnaires that assessed knee function and quality of life 2 to 14 years after injury. Their responses were compared with those of a matched cohort of their uninjured teammates. RESULTS: There were no differences in the mean Tegner scores, modified Lysholm scores, or in the scores of the SF-36 between groups. Sixteen anterior cruciate ligament-injured athletes scored A or B in the subjective portion of the International Knee Documentation Committee score and 17 scored C or D, whereas 24 control subjects scored A or B and 9 scored C or D, a statistically significant difference between groups. Five injured and 14 control athletes had participated at a professional or national team level after college. CONCLUSIONS: Quality of life of elite collegiate athletes who sustained an anterior cruciate ligament injury was not significantly different from that of their uninjured teammates, but knee function differed between groups.

Relaxin receptors in the human female anterior cruciate ligament.

BACKGROUND: Noncontact anterior cruciate ligament injuries occur two to eight times more often in women than in men. Changes in ligament laxity and strength have been associated with female hormones such as relaxin. HYPOTHESIS: Relaxin receptors are present within the female anterior cruciate ligament. STUDY DESIGN: Controlled laboratory study. METHODS: Remnants of anterior cruciate ligament were harvested from five women and five men undergoing routine ligament reconstruction. Relaxin was biotinylated and analyzed for biologic activity with use of the mouse interpubic ligament bioassay. Immunohistochemical localization of relaxin receptors was performed with appropriate negative controls and competitive binding assays to determine receptor specificity and saturability. RESULTS: Anterior cruciate ligament sections from women but not from men showed uniform specific binding that was limited to synovial lining cells, stromal fibroblasts, and cells lining blood vessels. Specific binding was confirmed in the presence of a 2000-fold excess of human insulin, the structural homolog of relaxin, and competitive inhibition was demonstrated in the presence of a 2000-fold excess of unlabeled relaxin. CONCLUSIONS: Relaxin exhibits specific saturable binding in the female anterior cruciate ligament, where specific relaxin receptors were present. CLINICAL RELEVANCE: The high incidence of anterior cruciate ligament rupture in female athletes may be partially explained by the effects of relaxin.

Patients' reasons for undergoing total hip arthroplasty can change over time.

The purpose of this study was to determine if a patient's reasons for undergoing a primary total hip arthroplasty (THA) changed at 1 year follow-up and, if the reasons did change, how does this change influence patient satisfaction with the procedure. Patients undergoing THA (101 patients) were evaluated with the McMaster Toronto Arthritis Patient Preference Disability (MACTAR) questionnaire and questions related to their expectations regarding the procedure. With the exception of pain and walking, most patients did not select the same preoperative and postoperative reasons for undergoing the procedure. In fact, 60% chose 2 new postoperative items. Patients whose expectations were not met were less likely to choose the same reasons for undergoing THA. Surgeons need to clarify patients' reasons for wanting a THA and attempt to identify new factors at follow-up that may influence patient satisfaction with the procedure.

Effects of femoral tunnel placement on knee laxity and forces in an anterior cruciate ligament graft.

The purpose of this study was to measure the effects of variation in placement of the femoral tunnel upon knee laxity, graft pretension required to restore normal anterior-posterior (AP) laxity and graft forces following anterior cruciate ligament (ACL) reconstruction. Two variants in tunnel position were studied: (1) AP position along the medial border of the lateral femoral condyle (at a standard 11 o'clock notch orientation) and (2) orientation along the arc of the femoral notch (o'clock position) at a fixed distance of 6-7 mm anterior to the posterior wall. AP laxity and forces in the native ACL were measured in fresh frozen cadaveric knee specimens during passive knee flexion-extension under the following modes of tibial loading: no external tibial force, anterior tibial force, varus-valgus moment, and internal-external tibial torque. One group (15 specimens) was used to determine effects of AP tunnel placement, while a second group (14 specimens) was used to study variations in o'clock position of the femoral tunnel within the femoral notch. A bone-patellar tendon-bone graft was placed into a femoral tunnel centered at a point 6-7 mm anterior to the posterior wall at the 11 o'clock position in the femoral notch. A graft pretension was determined such that AP laxity of the knee at 30 deg of flexion was restored to within 1 mm of normal; this was termed the laxity match pretension. All tests were repeated with a graft in the standard 11 o'clock tunnel, and then with a graft in tunnels placed at other selected positions. Varying placement of the femoral tunnel 1 h clockwise or counterclockwise from the 11 o'clock position did not significantly affect any biomechanical parameter measured in this study, nor did placing the graft 2.5 mm posteriorly within the standard 11 o'clock femoral tunnel. Placing the graft in a tunnel 5.0 mm anterior to the standard 11 o'clock tunnel increased the mean laxity match pretension by 16.8 N (62%) and produced a knee which was on average 1.7 mm more lax than normal at 10 deg of flexion and 4.2 mm less lax at 90 deg. During passive knee flexion-extension testing, mean graft forces with the 5.0 mm anterior tunnel were significantly higher than corresponding means with the standard 11 o'clock tunnel between 40 and 90 deg of flexion for all modes of constant tibial loading. These results indicate that AP positioning of the femoral tunnel at the 11 o'clock position is more critical than o'clock positioning in terms of restoring normal levels of graft force and knee laxity profiles at the time of ACL reconstruction.