paper 135: biomechanical study and preliminary results for a newly developed arthroscopic...

two groups: Group A: arthroscopic procedure with amedial parapatellar portal, 11 patients, 1 male and 10females, mean age 30 years (15-42) and Group B: mini-invasive procedure with a medial parapatellar incision,11 patients, all females, mean age 25 years (15-36).

The indication for surgical treatment was patellar in-stability in 19 patients, and recurrent patellar luxation in3 patients (all in group A).

Results were evaluated with the Fulkerson-Shea scale.Postoperative results after a mean follow-up of 70months (57-86). Group A: excellent 10 cases and fair 1.Group B: excellent 10 cases and good 1 with no recur-rence of subluxation or luxation. The indication for thissimple arthroscopic procedure is patellar instability with-out distal malalignment. Proximal realignment can beperformed safely arthroscopically.

Paper 135: Biomechanical Study and Preliminary Re-sults for a Newly Developed Arthroscopic Coracocla-vicular Ligament Reconstruction Using TendonGraft YONSIK YOO, MD, PHD, SOUTH KOREA, PRESENTING

AUTHOR

DOYOUNG KIM, MD, SOUTH KOREA

ANIL S. RANAWAT, MD, USAMARK WILLIAM RODOSKY, MD, USA

ABSTRACTAlthough more than 100 surgical techniques have been

reported, there is no gold standard for the treatment ofacromioclavicular joint dislocations. Furthermore, manyof these techniques replace or reconstruct the coracocla-vicular (CC) ligaments with one structure but do notaccount for the native two bundle anatomy of the CCligaments. This finding has led us to design a newmethod of CC ligament reconstruction using an anatomictwo bundle CC ligament reconstruction using a threetunnel technique and allograft tissue. The purpose of thisstudy was to evaluate the biomechanical performance ofthis new double bundle, anatomic reconstruction in ca-davers and to show the preliminary short term clinicalresults of this technique that was applied to patients whohad AC dislocation with over grade III in Rockwoodclassification. Ten cadaveric shoulders were tested usinga robotic/UFS testing system with 6-degree-of-freedomuniversal force/moment sensor (UFS-Model 4015; JR3Inc. Woodland, CA). Biomechanical properties of thecoracoclavicular ligament reconstructions and kinemat-ics of AC joint were tested using this robotic system andcompared to measurements from the native coracocla-vicular ligaments. The trapezoid ligament had forces of19.18�16.21 N and 56.03�17.80 N in the anterior andposterior load of 70N, respectively, and was significantly

different from the conoid ligament (p�0.0022, 0.0012),which had in situ forces of 52.41�15.90 N and15.53�18.06 N. The mean anterior, posterior, and supe-rior displacement after anatomical CC reconstruction incadaver was 7.24�3.24 mm, 6.41�3.67 mm, and4.29�2.52 mm, respectively. There was no differencecompared with the AC deficient shoulder which is de-fined as a control: p � .9064, .0729, .1328, respectively.

Also our study include 10 symptomatic shoulders(M/F: 7/3) with mean ages of 25.5 years who had X rayevidence of wide AC separation. All patients had painfulrestricted ROM and tenderness on the AC joint. Ournovel technique was used to all patients. The semitendi-nosis tendon was harvested and passed through the cor-acoid via a drill tunnel placed at the anatomical footprintof the conoid ligament and then taken superolaterallythrough the clavicle to reconstruct the trapezoid liga-ment. Both ends of the tendon graft and the portion of thegraft through the corocoid were secured using 5.5x8 mmPEEK screws by means of three point fixation. All pa-tients were submitted to the same rehabilitation programand assessed subjectively and objectively after 3 monthsof the surgery using VAS, simple shoulder muscle powertest, patient satisfaction and radiologic finding. All pa-tients were remained pain-free with significant improvedfunction and very satisfied with the results of this pro-cedure. Mean displacement of distal clavicle on medialtip of acromion in simple shoulder AP radiograph was2.1�1.8 mm at final follow up. No complication andinfection was noted. In conclusion, the conoid and trap-ezoid ligaments were found to have different roles inhorizontal motion of clavicle. Therefore, anatomicaldouble-bundle reconstruction of both ligaments shouldbe considered to properly restore of native kinematicsafter the AC joint injury.

Paper 136: Arthroscopic Repair of Medial Retinacu-lum Ruptures Associated with Acute Patella Disloca-tions LAUREN H. REDLER, BS, USA, PRESENTING AUTHOR

MICHAEL R. REDLER, MD, USASTEVEN P. FRIES, PA-C, USA

ABSTRACTAcute patellar dislocation in athletes is a well-recog-

nized entity that can cause significant impairment bothacutely as well as long term. Treatment options for aninitial patella dislocation include immobilization, func-tional treatment or surgical repair. The rationale for eachtreatment choice is dependent on the nature of the injury;including the associated intra-articular damage, predis-posing extensor mechanism malalignment as well theindividual surgeon’s preference. In instances when pre-

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