Anthony Miniaci

The outcome of operatively treated anterior cruciate ligament disruptions in the skeletally immature child

Abstract The purpose of this study was to evaluate the outcome of transphyseal ligament reconstruction in skeletally immature children with midsubstance anterior cruciate ligament (ACL) disruption. Five consecutive patients (mean age, 12.9 years; range, 8 to 14 years) with radiographically documented wide open growth plates and a minimum of 5 cm of expected remaining growth, underwent intraarticular reconstruction of the ACL. Operative treatment included three ACL reconstructions using hamstring tendons and two with quadriceps patellar tendon. All involved a centrally placed 6-mm or smaller tibial drill hole through an open physis and graft placement in an over-the-top position on the femur. At an average follow-up of 7.4 years (range, 4.5 to 9.9 years), no patient had a positive anterior drawer, Lachman, or pivot shift test. On KT- 1000 arthrometer testing, all patients had 3 mm or less of increased anterior-posterior displacement (mean ± SD=1.0 ± 1.6 mm). Magnetic resonance imaging showed that four tibial physes had fused in a symmetric fashion and one was still open. Orthoroentgenograms showed that no patient had a significant leg length discrepancy (−0.8 mm ± 3.4 mm). The mean increase in height postoperatively was 17.7 cm (range, 7.6 to 31.0 cm). Overall, using the International Knee Documentation Committee (IKDC) evaluation form, there were four patients with grade A and one with grade C. The one patient with a poor IKDC grade had sustained a subsequent patellar dislocation with osteochondral fracture. In conclusion, ACL reconstruction using small drill holes placed through open tibial physes does not seem to adversely affect outcome or future growth.

Magnetic Resonance Imaging Evaluation of the Rotator Cuff Tendons in the Asymptomatic Shoulder

Thirty shoulders in 20 volunteers (average age, 29 years; range, 17 to 49) with no shoulder symptoms or known abnormalities were scanned using magnetic resonance imaging. All scans were interpreted by one radiologist who was blinded to clinical data. Appearance of rotator cuff tendons on the images was graded. Grade 0 was normal, homogeneous low signal intensity structure. Grade 1 lesion was focal, linear, or diffuse intermediate signal through the tendon. Grade 2 lesion was high signal intensity within the tendon and less than full thickness. Grade 3 was high signal intensity through the full thickness of the tendon. No supraspinatus or infraspinatus tendons were grade 0 (normal); all su praspinatus and infraspinatus tendons had grade 1 changes through the tendons; and 7 of 30 (23%) of the tendons had grade 2 changes. None of the 30 shoulders had grade 3 changes in the rotator cuff tendons. There is a wide array of abnormal magnetic resonance imag ing signals in shoulders of young asymptomatic indi viduals, but they do not have full-thickness rotator cuff tears (grade 3 lesion). Nonenhanced magnetic reso nance imaging may be of limited value in defining rotator cuff injury in a patient with shoulder pain unless a full- thickness rotator cuff tear is suspected clinically.

The Effect of Cast Immobilization on Meniscal Healing An Experimental Study in the Dog

A 1.5-cm longitudinal, full-thickness incision was made in the vascularized portion of the medial meniscus in 20 adult dogs and anatomically repaired. Postoperatively, the animals were either placed in a long leg cast (N = 9) or mobilized immediately (N = 11). The animals were sacrificed at 2 weeks (6 dogs), 4 weeks (6 dogs), or 10 weeks (8 dogs). Five medial menisci from the nonop erated side were used as controls. Collagen content was measured using a digital image analysis system, and the collagen percentage in the repair tissue in each postoperative treatment group was compared. In the 2-week and 4-week groups, there was no statistically significant difference in the percentage of collagen be tween those animals immobilized versus those that had early mobilization. The animals in the 10-week group that were mobilized had a significantly greater collagen percentage in the healing meniscal incision than those that were cast immobilized (44.6% ± 10% versus 27.0% ± 11 %, P < 0.0001). There was no significant difference in the collagen percentages between the mo bilized 10-week group and the contralateral control me nisci group. All other menisci had a decreased collagen percentage compared with the controls. Prolonged im mobilization decreases collagen formation in healing menisci. Thus, our results suggest that patients under going isolated meniscal repair either be immediately mobilized after surgery or immobilized for short periods only.

Ligament Tension Affects Nuclear Shape in Situ: An in Vitro Study

This study was carried out to test the hypothesis that a relationship exists between ligament tension and ligament cell geometry. Rabbit knee joints were positioned at 70 degrees of joint flexion and the medial collateral ligament (MCL) was mechanically isolated and the femur-MCL-tibia complex was stretched or compressed by displacing the crosshead of a materials testing machine: -2.0 mm (relative compression), 0.0 mm (a reproducible no-load starting point), +/-0.7 mm or + 1.4 mm (relative tension). Each MCL complex was then fixed immediately in 10% neutral buffered formalin. Contralateral knees were dissected similarly with MCLs exposed and fixed in situ at 70 degrees of flexion. Subsequent to histological processing, measurements were made of the profiles of fibrocyte nuclei (since previous work has shown that nuclear shape closely approximates fibrocyte shape) that were located in the central portion of each MCL midsubstance using a video-based computerized morphometry system. Results showed that the dimensions of nuclei in the midsubstance of experimental MCLs were significantly longer and thinner at crosshead displacements that corresponded to increased ligament tension. At +1.4 mm of displacement fibrocyte nuclei were approximately 4 microm longer and 1 microm thinner than those fixed at 0.0 mm, an observation supported by a statistically significant increase in the mean maximum-to-minimum-diameter ratio and a significant decrease in mean cell roundness. These results strongly suggest that mechanical load can directly affect ligament fibrocyte geometry in situ. If a similar phenomenon also occurs in vivo, the metabolism of ligament fibrocytes may be influenced considerably by their loading history.

Editorial Commentary: Distal Tibia Allograft as an Option for Glenoid Reconstruction in Recurrent Shoulder Instability—It's All About the Bone?

Bony defects in recurrent shoulder instability can lead to the failure of soft tissue reconstruction. Many techniques have been developed to address glenoid defects in an attempt to prevent recurrent instability. However, the high complication rates with the Latarjet procedure have led surgeons to identify other sources of bone graft, including the distal tibia allograft (DTA). The DTA appears to be a suitable option for anterior glenoid reconstruction, highlighting the importance of reconstructing all bony defects and the versatility and efficacy of allograft bone blocks.

Mechanical Axis and Bone Marrow Lesions in Knee Osteoarthritis

Objectives: The goal of the present study was to assess bone marrow lesions (BML) present in knee osteoarthritis and determine if knee alignment influences their presence and severity. Methods: Data were taken from the progression subcohort of the Osteoarthritis Initiative. The Osteoarthritis Initiative (OAI) is a multi-center, four-year observational study of men and women focusing on OA incidence and progression. One hundred and forty patients were randomly sampled from the progression subcohort of the OAI. For each patient, the leg with the worst average KOOS Knee Pain Score was chosen for analysis. Using custom software written in MATLAB (The Mathworks Inc., Natick, MA), the mechanical axis and hip-knee-angle were identified on full-limb x-rays. Fulllimb x-ray images were registered to coronal multiplanar reconstruction MR images using three control points. The location of the mechanical axis was mapped onto the knee MRI ́s. Using a separate custom software tool, BML ́s were marked by medial, lateral, superior and inferior borders on coronal and sagittal MRI. Area and volume of each BML were modeled as ellipses and ellipsoids respectively. The minimum distance between the center of each BML on the mechanical axis was also calculated. Results: Of the 140 patients sampled, 100 patients had full-limb radiographs and MRIs. Of these, 71 patients were noted to have bone marrow lesions. The average age of this group was 65 (SD: 9). In these patients, a total of 144 bone marrow lesions were identified. The average bone marrow lesion had a volume of 108.7 mm3 (SD of 233.4) and was 16.25 mm (SD: 11.2) from the mechanical axis. There was no statistically significant correlation between BML size, location and knee alignment. Conclusions: Our results suggest that there is little-to-no correlation between knee alignment and the presence and severity of bone marrow lesions in knee osteoarthritis. To our knowledge, this is the first quantitative study of the relationship between the mechanical axis, hip-knee-angle and bone marrow lesions presence and size. While it is surprising that we found no relationship between bone marrow lesion location/size and the position of the mechanical axis, it suggests that BML pathogenesis is more complex than previously thought. Further study into the influence of cartilage and meniscus status as well as time on this relationship is warranted.