Quadriceps muscle activation and radiographic osteoarthritis following ACL revision.

PURPOSE: Quadriceps strength and activation may play an important role in the recovery from ACL revision surgery. The purpose of this study was to describe quadriceps strength and central activation ratio (CAR) and correlate with radiographic findings in patients with ACL revision surgery. METHODS: Twenty-one patients who were on average 47.5 ± 21.1 months [range: 14-85 months] post-revision ACL reconstruction. We performed knee joint physical examination and radiographic evaluation. Quadriceps strength testing consisted of maximal voluntary isometric contractions (MVIC) with the knee bent to 90-degrees bilaterally. We calculated quadriceps central activation ratio using the superimposed burst technique. Radiographs (bilateral standing antero-posterior in knee flexion and lateral in full extension) were evaluated by a fellowship-trained orthopedic surgeon using the International Knee Documentation Committee (IKDC) grading system. RESULTS: Mean CAR was 83.9 ± 12.0% on the reconstructed limb and 85.5 ± 9.5% on the contralateral limb. Average, normalized MVIC torque was 2.5 ± 1.0 Nm/kg on the reconstructed limb and 2.7 ± 1.0 N m/kg for the contralateral limb. Patient age at the time of follow-up evaluation was related to severity of knee joint degeneration, particularly the medial, anterior and patellofemoral compartments. Younger patients with lower CARs tended to have more severe degeneration in the patellofemoral joint. Older patients with lower normalized MVIC torque values tended to exhibit more severely graded degeneration in the patellofemoral joint. CONCLUSION: Bilateral quadriceps central activation deficits and radiographic osteoarthritis are evident in patients with revision ACL reconstruction.

Multiple ligament knee reconstruction clinical follow-up and gait analysis.

Multiple ligament knee injuries are serious and rare injures that have not been studied using advanced gait analysis techniques. The purpose of this study was to perform clinical follow-up and gait analysis on patients with multiple knee ligament reconstruction. Twenty-four patients who underwent a multi-ligament knee reconstruction by a single surgeon volunteered to participate in this study. We performed complete clinical exam including instrumented ACL exam (KT-1000), and radiological exam including weight-bearing and PCL stress radiographs (TELOS) at minimum 2 years post index surgery. In addition, we performed complete three-dimensional gait analysis on 18 patients. We used a 10-camera, high speed (120 Hz) motion analysis system in conjunction with a multi-axis strain-gage force plate which calculated knee joint kinetics and kinematics while subjects performed flat-ground walking and stair-descent tasks. Kinematic and kinetic variables were compared between reconstructed and contralateral knees and unmatched, healthy control knees. All knee joint moments were normalized to subjects' weight. Clinical: Average knee joint flexion/extension 123.6 +/- 15.5/1.7 +/- 3.5, respectively. Average KT-1000 side-to-side difference was 1.2 +/- 2.0 mm, TELOS side-to-side difference on stress radiographs was 4.0 +/- 3.1 mm. Median IKDC score was 67 (range 13-94). Fifty-three percent of patients exhibited radiographic evidence of osteoarthritis (OA) on the operative side; one patient on the contralateral knee. During gait analysis, patients exhibited significantly reduced total knee joint range of motion, and external knee flexion moment in the reconstructed knee compared to the contralateral knee and healthy control knees. The magnitude of these differences was greater while descending a step. Finally, patients who had radiographic evidence of knee joint OA had significantly lower magnitude external knee flexion moment compared to those who did not have OA at the time of follow-up. Greater than 2 years after reconstruction, patients with multi-ligament knee injuries are able to return to daily activities. Gait analysis data suggests that patients may be experiencing higher magnitude changes in sagittal plane kinematics and kinetics during demanding functional tasks (stair decent). Changes in walking gait biomechanics may help explain why this group is experiencing unilateral knee joint degeneration.

Donor-site giant cell reaction following backfill with synthetic bone material during osteochondral plug transfer.

Osteochondral defects are common in younger, active patients. Multiple strategies have been used to treat these lesions, including microfracture and osteochondral plug transfer. We describe a patient experiencing chronic knee pain and a full-thickness cartilage defect on the lateral femoral condyle. After failing conservative management and microfracture surgery, the patient underwent osteochondral autograft plug transfer, with backfilling of the donor sites using synthetic bone graft substitute. Initial recovery was uncomplicated until the patient experienced pain following a twist of the knee. Magnetic resonance imaging for the subsequent knee injury revealed poor healing at the donor sites. The donor sites were debrided, and specimens revealed a foreign body giant cell reaction. Donor-site morbidity is of primary concern during osteochondral plug transfer; however, insufficient data exist to support the use of synthetic bone graft material. Our results indicate that off-label use of synthetic bone graft substitute during a primary procedure requires further investigation.

All-inside meniscal repair using a new flexible, tensionable device.

BACKGROUND: A new generation of flexible all-inside meniscal repair devices is available, but clinical studies with these devices are lacking. HYPOTHESIS: The RapidLoc has an intermediate-term meniscal healing rate that is equivalent to literature reports of inside-out suture technique in patients undergoing concurrent anterior cruciate ligament reconstruction. STUDY DESIGN: Case series; Level of evidence, 4. METHODS: Retrospective analysis was performed for 75 meniscal tears in 66 consecutive patients undergoing anterior cruciate ligament reconstruction who underwent meniscal repair with the RapidLoc. Patients with at least 2 years' follow-up were evaluated for symptoms suggestive of a meniscal tear and were assessed with the International Knee Documentation Committee form and the Knee Disorders Subjective History visual analog scale. Subjects were asked to return for a clinical examination to include evaluation for an effusion and joint line tenderness as well as McMurray test and KT-1000 arthrometry readings. Patients with symptoms consistent with meniscal repair failure underwent magnetic resonance arthrography and repeat arthroscopy. RESULTS: Twenty patients with 21 meniscal tears were excluded, resulting in 54 meniscal tears in 46 patients. At a mean follow-up of 34.8 months, the clinical success rate for meniscal repair was 90.7% (49/54), with 5 failures requiring meniscectomy. Univariate analysis revealed predictive variables for failure: bucket-handle configuration, multiplanar tears, tear length greater than 2 cm, and chronicity longer than 3 months. Non-predictive variables included compartment, zone, ligament graft choice, gender, age, follow-up, and visual analog scale score. Analysis of healed patients revealed a negative correlation between chronicity of tear and International Knee Documentation Committee score. CONCLUSIONS: The RapidLoc has an acceptable intermediate-term clinical healing rate in patients undergoing concurrent anterior cruciate ligament reconstruction. Predictive variables for failure should be considered during operative decision making.

All-inside meniscal repair.

All-inside meniscal repair has become a popular technique. The number of meniscal repairs done in the United States has increased dramatically since the introduction of the Meniscal Arrow (Linvatec Corp, Largo, FL). Although these devices are easy to use, there have been several compliations reported with their use. Newer devices (Mitek RapidLoc and Smith and Nephew Fas-T-Fix) allow tensioning of the construct after insertion. There are also problems and pitfalls with their use, but improvements continue to be made in all-inside meniscal repair devices.

Physical examination of the knee.

Even with the rapid advancement in technology and medical imaging, there is still no substitute for the history and physical examination that can be obtained from a patient. With a well-performed history and physical, the majority of pathology can be determined prior to any expensive imaging or surgical procedures. The knee is one of the most commonly injured joints, and its function is critical to basic ambulation and participation in sports, work, and activities of daily living. This article reviews the key concepts to a complete evaluation of the knee and highlights aspects of the physical examination and radiographic imaging that best aid in diagnosing knee pathology.

Hyaluronic acid viscosupplementation and osteoarthritis: current uses and future directions.

Intra-articular hyaluronic acid viscosupplementation is gaining popularity as a treatment option in the nonoperative management of patients with osteoarthritis. Recent clinical studies have demonstrated that the anti-inflammatory, anabolic, and chondroprotective actions of hyaluronic acid reduce pain and improve patient function. With evidence mounting in support of the efficacy of this treatment modality for patients with osteoarthritis, its potential use in additional patient populations and for other pathologies affecting the knee is being investigated. The current article reviews the use of intra-articular hyaluronic acid viscosupplementation in the management of knee osteoarthritis and presents the potential for expanding its indications for other joints and alternative patient subpopulations. Additionally, future directions for the use of hyaluronic acid and areas of active research are discussed.

Tunnel widening following anterior cruciate ligament reconstruction using hamstring autograft: a comparison between double cross-pin and suspensory graft fixation.

Femoral and tibial tunnel widening following ACL reconstruction using hamstring autograft has been described. Greater tunnel widening has been reported with suspensory fixation systems. We hypothesized that greater tunnel widening will be observed in patients whose hamstring autograft was fixated using a cortical, suspensory system, compared to double cross-pin fixation on the femur. We performed clinical and radiographic evaluation on 46 patients at minimum 2 years after primary ACL reconstruction. We measured subjective and objective outcomes including KT-1000 and AP, lateral radiographs. A musculoskeletal radiologist, independent of the surgical team, measured tunnel width, while correcting for magnification, at the widest point and at 1 cm away from tibial and femoral tunnel apertures. Patients in the suspensory graft fixation group exhibited significantly greater absolute change and greater percent change in femoral tunnel diameter compared to patients with double cross-pin fixation (P