Effect of Osteochondroplasty on Time to Reoperation After Arthroscopic Management of Femoroacetabular Impingement: Analysis of a Randomized Controlled Trial.

Background: A subset of patients with femoroacetabular impingement (FAI) fail arthroscopic management. It is not clear which patients will fail surgical management; however, several surgical and patient factors, such as type of procedure and age, are thought to be important predictors. Purpose: This time-to-event analysis with a 27-month follow-up analysis compared the effect of (1) arthroscopic osteochondroplasty with or without labral repair versus (2) arthroscopic lavage with or without labral repair on the time to reoperation in adults aged 18 to 50 years with FAI. Study Design: Randomized controlled trial; Level of evidence, 1. Methods: Eligible participants had been randomized in a previous study trial to a treatment of arthroscopic osteochondroplasty or arthroscopic lavage with or without labral repair. Using the comprehensive data set from the Multinational Femoroacetabular Impingement Randomized controlled Trial, all reoperations until 27 months after surgery were identified. The analysis was conducted using a Cox proportional hazards model, with percentage of patients with a reoperation evaluated in a time-to-event analysis as the outcome. The independent variable was the procedure, with age and impingement subtype explored as potential covariates. The effects from the Cox model were expressed as the hazard ratio (HR). All tests were 2-sided, with an alpha level of .05. Results: A total of 108 patients in the osteochondroplasty group and 106 patients in the lavage group were included. The mean age of the patients included in the study was 36 ± 8.5 years. Overall, 27 incident reoperations were identified within the 27-month follow-up, with an incidence rate of 6 per 100 person-years. Within the osteochondroplasty group, 8 incident reoperations were identified (incidence rate, 3.4 per 100 person-years), while within the lavage group, 19 incident reoperations were identified (incidence rate, 8.7 per 100 person-years). The hazard of reoperation for patients undergoing osteochondroplasty was 40% of that of patients undergoing lavage (HR, 0.40 [95% CI, 0.17-0.91] P = .029). Conclusion: This study demonstrated that for adults between the ages of 18 and 50 years with FAI, arthroscopic osteochondroplasty was associated with a 2.5-fold decrease in the hazard of reoperation at any point in time compared with arthroscopic lavage. Registration: NCT01623843 (ClinicalTrials.gov identifier).

Osteochondroplasty and Labral Repair for the Treatment of Young Adults With Femoroacetabular Impingement: A Randomized Controlled Trial.

BACKGROUND: Femoroacetabular impingement (FAI) is a condition known to cause hip pain in young adults. PURPOSE: To evaluate the efficacy of the surgical correction of FAI via arthroscopic osteochondroplasty with or without labral repair compared with arthroscopic lavage of the hip joint with or without labral repair. STUDY DESIGN: Randomized controlled trial; Level of evidence, 1. METHODS: A total of 220 male and female participants aged 18 to 50 years with nonarthritic FAI suitable for surgical treatment were recruited for the trial at 10 clinical centers in Canada, Finland, and Denmark between October 2012 and November 2017, of whom 214 were included in the final analysis. In the osteochondroplasty group, cam- and/or pincer-type lesions were resected using fluoroscopic guidance. In the lavage group, the joint was washed out with 3 L of normal saline. Surgeons were instructed to repair the labrum in both groups if it was mechanically unstable once probed, showing visible displacement or chondrolabral separation. The primary outcome was patient-reported pain (using the 100-point visual analog scale [VAS]) at 12 months. Secondary outcomes included hip function (Hip Outcome Score [HOS] and International Hip Outcome Tool), physical and mental health (12-Item Short Form Health Survey), and health utility (EuroQol-5 Dimensions) at 12 months as well as any reoperations and other hip-related adverse events at 24 months. RESULTS: At 12 months, there was no difference in pain (VAS) between the groups (mean difference [MD], 0.11 [95% CI, -7.22 to 7.45]; P = .98). Also, 88.3% (189/214) of participants had a labral tear, of which 60.3% were repaired. For the secondary outcomes, there were no significant differences between treatment groups, with the exception of the HOS activities of daily living domain in which lavage showed significant improvement compared with osteochondroplasty (MD, -5.03 [95% CI, -10.40 to -0.03]; P = .049). By 24 months, there were significantly fewer reoperations reported in the osteochondroplasty group (8/105) than the lavage group (19/104) (odds ratio, 0.37 [95% CI, 0.15-0.89]; P = .026). The primary reasons for a reoperation included hip pain (15/27; 55.6%) and a reinjury of the labrum (11/27; 40.7%). CONCLUSION: Both the osteochondroplasty and the lavage groups with or without labral repair for FAI had significantly improved pain or function significantly at 1 year. By 2 years, the reoperation rate was significantly lower in the osteochondroplasty group. REGISTRATION: NCT01623843 (ClinicalTrials.gov identifier).

Effect of muscle loads and torque applied to the tibia on the strain behavior of the anterior cruciate ligament: an in vitro investigation.

BACKGROUND: Very little is known about the effects of applied torque about the long axis of the tibia in combination with muscle loads on anterior cruciate ligament biomechanics. The purpose of this study was to determine the effect of muscle contraction and tibial torques applied about the long axis of the tibia on anterior cruciate ligament strain behavior. METHODS: Six cadaver knee specimens were used to measure the strain behavior of the anterior cruciate ligament. Internal and external axial torques were applied to the tibia when the knee was between 30° and 120° of flexion in combination with the conditions of no muscle load, isolated quadriceps load, and simultaneous quadriceps and hamstring loading. FINDINGS: The highest anterior cruciate ligament strain values were measured when the muscles were not loaded, when the knee was at 120° of flexion, and when internal tibial torques were applied to the knee. During muscle loading the highest anterior cruciate ligament strain values were measured at 30° of flexion and then the strain values gradually decreased with increase in knee flexion. During co-contraction of the quadriceps and hamstring muscles the anterior cruciate ligament was unstrained or minimally strained at 60°, 90° and 120° of knee flexion. INTERPRETATION: This study suggests that quadriceps and hamstring muscle co-contraction has a potential role in reducing the anterior cruciate ligament strain values when the knee is in deep flexion. These results can be used to gain insight into anterior cruciate ligament injury mechanisms and to design rehabilitation regimens.

Geographic mapping of meniscus and cartilage lesions associated with anterior cruciate ligament injuries.

BACKGROUND: Detailed descriptions of meniscus and articular cartilage lesions associated with anterior cruciate ligament injury have not been presented in the literature. Our goal was to determine the associations between patient sex, age, and surgical delay and the frequency and location of meniscus and articular cartilage lesions seen at the time of the anterior cruciate ligament reconstruction. METHODS: Data were obtained retrospectively from a database of 1209 consecutive patients undergoing anterior cruciate ligament reconstruction between 1988 and 2002. All knee cartilage, meniscus, and ligament injuries were documented on anatomic maps at the time of surgery, and the data were analyzed. RESULTS: Meniscus injuries were identified in 722 (65%) of the 1104 patients who met the criteria for inclusion in the study. Female patients were less likely to have a meniscus injury than male patients were (56% compared with 71%), and male patients were more likely to have combined medial and lateral meniscus injuries than female patients were (20% compared with 11%). Patients with a surgical delay of less than three months were less likely to have a medial meniscus injury (8% compared with 19%). Femoral articular cartilage injuries were identified in 472 patients (43%). Patients who were twenty-five years of age or older were more likely to have multiple cartilage lesions throughout the knee (7.7% compared with 1.3%) and to have more isolated medial femoral condyle lesions (24.2% compared with 13.3%). Patients with a surgical delay of more than one year were more likely to have a lesion (60% compared with 47% for all others), and a surgical delay of more than one year resulted in a greater proportion of large and grade-3 lesions of the lateral femoral condyle. Female patients had a greater proportion of grade-1 lesions of the medial femoral condyle (29% compared with 16%), whereas male patients had a greater proportion of grade-3 and 4 lesions of the medial femoral condyle (49% compared with 35%). In patients who were thirty-five years of age or older, meniscus injuries were more frequent and were located more frequently on the medial side; femoral articular cartilage lesions were also located more frequently on the medial side. CONCLUSIONS: Increased age, male sex, and increased surgical delay all increase the frequency and severity of injuries of the meniscus and/or articular cartilage after an anterior cruciate ligament tear.

The fixation strength of six hamstring tendon graft fixation devices in anterior cruciate ligament reconstruction. Part I: femoral site.

BACKGROUND: Strength of graft fixation is the weakest link in anterior cruciate ligament reconstruction. HYPOTHESIS: There is no difference in initial fixation strength between different hamstring tendon graft femoral fixation devices. STUDY DESIGN: Randomized experimental study. METHODS: Each of six devices was used in the fixation of 10 quadrupled human semitendinosus-gracilis tendon grafts in tunnels drilled in porcine femora and tested 10 times with a single-cycle load-to-failure test at a rate of 50 mm/min and 10 times with a 1500-cycle loading test between 50 and 200 N at one cycle every 2 seconds. The specimens that survived the cyclic loading were subjected to a single-cycle load-to-failure test. RESULTS: The Bone Mulch Screw (1112 N) was strongest in the single-cycle load-to-failure test, followed by EndoButton CL (1086 N), RigidFix (868 N), SmartScrew ACL (794 N), BioScrew (589 N), and RCI screw (546 N). It also showed the lowest residual displacement (2.2 mm) and was strongest in the single-cycle load-to-failure test after cyclic loading. CONCLUSIONS: The Bone Mulch Screw was superior to all other devices. CLINICAL RELEVANCE: Caution may be warranted in employing aggressive rehabilitation after reconstruction with these devices. Preconditioning of the graft-implant complex before fixation is important.

The fixation strength of six hamstring tendon graft fixation devices in anterior cruciate ligament reconstruction. Part II: tibial site.

BACKGROUND: Tibial fixation is more problematic than femoral fixation in anterior cruciate ligament reconstruction. HYPOTHESIS: There is no difference in initial fixation strength among hamstring tendon graft tibial fixation devices. STUDY DESIGN: Randomized experimental study. METHODS: Each of six devices used to fix 120 quadrupled human semitendinosus-gracilis tendon grafts into porcine tibiae was tested 10 times with a single-cycle load-to-failure test and 10 times with a 1500-cycle loading test. Specimens surviving cyclic loading were subjected to a single-cycle load-to-failure test. RESULTS: Intrafix (1332 N) was the strongest in the single-cycle load-to-failure test, followed by WasherLoc (975 N), tandem spiked washer (769 N), SmartScrew ACL (665 N), BioScrew (612 N), and SoftSilk (471 N). After cyclic-loading tests, Intrafix showed the lowest residual displacement (1.5 mm) and was also strongest (1309 N) in the single-cycle load-to-failure test after the cyclic-loading test, followed by WasherLoc (3.2 mm; 917 N). CONCLUSION: The Intrafix provided clearly superior strength in the fixation of hamstring tendon grafts to the tibial drill hole. CLINICAL RELEVANCE: Some caution may be warranted when using the implants that showed increased residual displacement, especially if aggressive rehabilitation is to be used. Preconditioning of the hamstring tendon graft-implant complex before tibial fixation is needed.