Bryan Haughom

Physical activity is associated with magnetic resonance imaging-based knee cartilage T2 measurements in asymptomatic subjects with and those without osteoarthritis risk factors.

OBJECTIVE To evaluate the association of exercise and knee-bending activities with magnetic resonance imaging (MRI)-based knee cartilage T2 relaxation times and morphologic abnormalities in asymptomatic subjects from the Osteoarthritis Initiative, with or without osteoarthritis (OA) risk factors. METHODS We studied 128 subjects with knee OA risk factors and 33 normal control subjects ages 45-55 years, with a body mass index of 18-27 kg/m(2) and no knee pain. Subjects were categorized according to exercise level, using the leisure activity component of the Physical Activity Scale for the Elderly, and by self-reported frequent knee-bending activities. Two radiologists graded the cartilage of the right knee on MR images, using the Whole-Organ MRI Score (WORMS). Cartilage was segmented, and compartment-specific T2 values were calculated. Differences between the exercise groups and knee-bending groups were determined using multiple linear and logistic regression models. RESULTS Among subjects with risk factors for knee OA, light exercisers had lower T2 values compared with sedentary and moderate/strenuous exercisers. When the sexes were analyzed separately, female moderate/strenuous exercisers had higher T2 values compared with sedentary individuals and light exercisers. Subjects without risk factors displayed no significant differences in T2 values according to exercise level. However, frequent knee-bending activities were associated with higher T2 values in both subjects with OA risk factors and those without OA risk factors and with more severe cartilage lesions in the group with risk factors. CONCLUSION In subjects at risk of knee OA, light exercise was associated with low T2 values, whereas moderate/strenuous exercise in women was associated with high T2 values. Higher T2 values and WORMS grades were also observed in frequent knee-benders, suggesting greater cartilage degeneration in these individuals.

Blood Management Strategies for Total Knee Arthroplasty

Perioperative blood loss during total knee arthroplasty can be significant, with magnitudes typically ranging from 300 mL to 1 L, with occasional reports of up to 2 L. The resultant anemia can lead to severe complications, such as higher rates of postoperative infection, slower physical recovery, increased length of hospital stay, and increased morbidity and mortality. Although blood transfusions are now screened to a greater extent than in the past, they still carry the inherent risks of clerical error, infection, and immunologic reactions, all of which drive the need to develop alternative blood management strategies. Thorough patient evaluation is essential to individualize care through dedicated blood management and conservation pathways in order to maximize efficacy and avoid associated complications. Interventions may be implemented preoperatively, intraoperatively, and postoperatively.

Magnetic Resonance Imaging Evaluation of Knee Kinematics After Anterior Cruciate Ligament Reconstruction With Anteromedial and Transtibial Femoral Tunnel Drilling Techniques

PURPOSE The purpose of this study was to use magnetic resonance (MR) imaging to evaluate the translational and rotational kinematics of anterior cruciate ligament (ACL) reconstructed knees with transtibial (TT) and anteromedial (AM) femoral tunnel drilling. METHODS ACL reconstruction was performed in 21 subjects: 12 with AM drilling (5 men and 7 women; mean age, 33 ± 9 years; imaged 18 ± 5 months after surgery) and 9 with TT drilling (5 men and 4 women; mean age, 32 ± 9 years; imaged 12 ± 8 months after surgery). Three-tesla MR imaging was obtained bilaterally at extension and 30° to 40° of flexion under simulated loading (125 N). MR images were segmented and kinematic calculations done with in-house MATLAB software (The MathWorks, Natick, MA). Translation and rotation of the tibia and the tibiofemoral contact area were measured. Statistical analysis treated reconstructed and contralateral knees as independent groups. Reconstructed groups were compared with analysis of covariance using contralateral knees as baseline. P < .05 indicated significance. RESULTS All kinematic measures in the AM group were similar to contralateral knees. The TT group showed significantly more total tibial rotation than contralateral knees (TT, 8.4° ± 3.9°; contralateral, 2.9° ± 6.8°) (P = .03), whereas the AM group did not (AM, 3.1° ± 5.6°; contralateral, 2.3° ± 5.4°) (P = .36). At knee extension, the tibia was more externally rotated in the TT group than in controls. Medial tibial translation was greater in the TT group than in controls. The AM group showed increased contact area in the lateral compartment compared with controls; no differences were seen in the TT group. CONCLUSIONS Using an MR-based approach, we found that knee kinematics were better restored with the AM femoral tunnel drilling ACL reconstruction than with the TT femoral tunnel drilling approach, which resulted in increased knee laxity. Our in vivo results support previous cadaveric and clinical studies that have found AM ACL reconstruction to restore anatomy and stability better than the TT approach. However, the clinical significance of increased contact area in the AM group remains unclear. LEVEL OF EVIDENCE Level III, retrospective comparative study.

Evaluating rotational kinematics of the knee in ACL reconstructed patients using 3.0 Tesla magnetic resonance imaging.

INTRODUCTION Injury to the anterior cruciate ligament (ACL) is common. While prior studies have shown that surgical reconstruction of the ACL can restore anterior-posterior kinematics, ACL-injured and reconstructed knees have been shown to have significant differences in tibial rotation when compared to uninjured knees. Our laboratory has developed an MR compatible rotational loading device to objectively quantify rotational stability of the knee following ACL injuries and reconstructions. Previous work from our group demonstrated a significant increase in total tibial rotation following ACL injuries. The current study is a prospective study on the same cohort of patients who have now undergone ACL reconstruction. We hypothesize that ACL reconstructed knees will have less tibial rotation relative to the pre-operative ACL deficient condition. We also hypothesize that ACL reconstructed knees will have greater rotational laxity when compared to healthy contralateral knees. METHODS Patients. Six of the ACL injured patients from our initial study who had subsequently undergone ACL reconstruction were evaluated 8.1 ± 2.9 months after surgery. All patients underwent single-bundle ACL reconstruction using anteromedial portal drilling of the femoral tunnel with identical post-operative regimens. Magnetic Resonance (MR) Imaging. Patients were placed in a supine position in the MR scanner on a custom-built loading device. Once secured in the scanner bore, an internal/external torque was applied to the foot. The tibiae were semi-automatically segmented with in-house software. Tibial rotation comparisons were made within subjects (i.e. side-to-side comparison between reconstructed and contralateral knees) and differences were explored using paired sample t-tests with significance set at p=0.05. RESULTS Regarding tibial rotation, in the ACL deficient state, these patients experienced an average of 5.9 ± 4.1° difference in tibial rotation between their ACL deficient and contralateral knees. However, there was a -0.2 ± 6.1° difference in tibial rotation of the ACL reconstructed knee when compared to the contralateral uninjured knee. Regarding tibial translation, ACL deficient patients showed a difference of 0.75 ± 1.4mm of anterior tibial translation between injured and healthy knees. After ACL reconstruction, there was a 0.2 ± 1.1mm difference in coupled anterior tibial translation of the ACL reconstructed knee compared to the contralateral knee. No significant differences in contact area between the two time points could be discerned. DISCUSSION The objective of our study was to assess the rotational laxity present in ACL reconstructed knees using a previously validated MRI-compatible rotational loading device. Our study demonstrated that ACL reconstruction can restore rotational laxity under load. This may speak to the benefit of an anteromedial drilling technique, which allows for a more horizontal and anatomically appropriate graft position.

Bilateral extensor mechanism disruption after total knee arthroplasty in two morbidly obese patients.

Disruption of the extensor mechanism as a result of patellar tendon or quadriceps tendon rupture is an uncommon but devastating complication after total knee arthroplasty. Treating a disrupted extensor mechanism can be challenging, particularly in patients who are morbidly obese, due to an increased risk of postoperative complications. Therefore, despite the debilitating nature of extensor mechanism disruption, many community surgeons do not feel comfortable pursuing more complex cases like revision total knee arthroplasty with extensor mechanism allograft on morbidly obese patients, and consequently many of these patients are referred to tertiary-care centers for reconstruction secondary to the complexity of this patient cohort. The authors report 2 cases of bilateral extensor mechanism disruption after total knee arthroplasty in patients who are morbidly obese. One patient experienced trauma leading to her initial rupture; however, her contralateral atraumatic disruption was subsequently diagnosed at a later date. The second patient did not experience trauma leading to either of her extensor mechanism disruptions. Despite substantial medical comorbidities and morbid obesity, revision total knee arthroplasties with extensor mechanism allografts were recommended in both cases in a staged bilateral fashion. The surgical technique is described and the unique challenges afforded by the marked obesity are detailed. The current literature on this subject is reviewed. Despite early complications related to recumbency, this report serves as an example of successful repairs of extensor mechanism disruptions in patients who are morbidly obese, suggesting that extensor mechanism allograft is viable even in patients with high risk of complications.

Arthroscopic T-capsulotomy for Excision of Pigmented Villonodular Synovitis in the Hip

Pigmented villonodular synovitis (PVNS) is a benign synovial tumor of unknown etiology with a predilection for the large joints of the appendicular skeleton. The poor prognosis for patients with hip disease is partially imparted by current surgical techniques. Recent advances in hip arthroscopy technique and instrumentation may enable arthroscopic treatment for PVNS in the hip. The authors report the first case where hip arthroscopy was used to surgically excise a biopsy-confirmed local PVNS lesion in the hip. Using selected capsular releases and accessory portals, the authors achieved adequate visualization and instrument mobilization to successfully excise the entire PVNS tumor with no identifiable complications.