Comparison of 2 surgical techniques for reconstructing posterolateral corner of the knee: a cadaveric study evaluated by navigation system.

PURPOSE: This study aimed to evaluate the immediate effect on knee kinematics by 2 different techniques of posterolateral corner (PLC) reconstruction. METHODS: Five intact formalin-preserved cadaveric knees were used in this study. A navigation system was used to measure knee kinematics (posterior translation, varus angulation, and external rotation) after application of a constant force and torque to the tibia. Four different conditions of the knee were evaluated during the biomechanical test: intact knee and PLC-sectioned knee and PLC-reconstructed knee by the double-femoral tunnel technique and single-femoral tunnel technique. RESULTS: Sectioning of the PLC structures resulted in significant increases in external rotation at 30° of flexion from 11.2° (SD, 2.6) to 24.6° (SD, 6.2), posterior translation at 30° of flexion from 3.4 mm (SD, 1.5) to 7.4 mm (SD, 3.8), and varus angulation at 0° of flexion from 2.3° (SD, 2.1) to 7.9° (SD, 5.1). Both reconstruction techniques significantly restored the varus stability. The external rotation and posterior translation at 30° of flexion after reconstruction with the double-femoral tunnel technique were 10.2° (SD, 1.3) and 3.4° (SD, 2.7), respectively, which were significantly better than those of the single-femoral tunnel technique. CONCLUSIONS: Both techniques of reconstruction showed improved stability compared with PLC-sectioned knees. The double-femoral tunnel technique in PLC reconstruction showed better rotational stability and resistance to posterior translation than the single-femoral tunnel technique without compromising varus stability. CLINICAL RELEVANCE: PLC reconstruction by a double-femoral tunnel technique achieves better rotational control and resistance to posterior translation.

Can MRI predict the clinical instability and loss of the screw home phenomenon following ACL tear?

Our purpose was to determine the relationship between tibiofemoral translation on magnetic resonance imaging and clinical instability of the knee following anterior cruciate ligament (ACL) injury. Within 66 patients (43 males, 23 females, mean age 30.25 years), 15 of 19 patients (80%) with an intact ACL had a demonstrable normal screw home movement, while 24 of 47 patients (51%) with an ACL tear had absence of the screw home movement. Patients with clinical instability had greater tibial translation and excursion at the lateral compartment (P=.0001). Following ACL injury, there is demonstrable absence of the normal screw-home movement with anterior tibial translation and excursion related to presence of clinical instability.

Knee rotational stability during pivoting movement is restored after anatomic double-bundle anterior cruciate ligament reconstruction.

BACKGROUND: The restoration of knee rotational stability after anatomic double-bundle anterior cruciate ligament (ACL) reconstruction has been demonstrated in the cadaveric model and with passive stress tests on humans but not yet with dynamic functional biomechanical tests performed by human participants. PURPOSE: To prospectively investigate the range of tibial rotation of ACL-deficient and ACL-reconstructed knees during a pivoting task. The authors hypothesized that there would be a significant increase in tibial internal rotation in the ACL-deficient knee compared with the contralateral knee and that the increased rotation would return to normal after anatomic double-bundle ACL reconstruction. STUDY DESIGN: Case series; Level of evidence, 4. METHODS: Ten men with unilateral ACL injury performed a high-demand jump-landing and pivoting task before and after ACL reconstruction with mean follow-up of 11 months. The range of tibial rotation of the injured, reconstructed, and intact knees during the pivoting movement was measured by an optical motion analysis system. Paired t tests were performed to investigate any significant difference between the 2 limbs preoperatively and postoperatively and within the injured limb before and after the surgical treatment. Statistical significance was set at P < .05. RESULTS: The range of tibial rotation was higher in the ACL-deficient knee (12.6° ± 4.5°) than in the intact knee (7.9° ± 3.1°) preoperatively (P < .05). The increased rotation was reduced in the reconstructed knee (8.9° ± 3.0°) after ACL reconstruction versus the intact knee postoperatively (8.2° ± 2.6°) (P < .05). There was no significant difference in the tibial rotation between the intact knee and the reconstructed knee postoperatively (P > .05). CONCLUSION: As assessed with a dynamic functional pivoting movement, the anatomic double-bundle ACL reconstruction successfully restores knee rotational stability from an impaired level.

Review of knee arthroscopy performed under local anesthesia.

Local anesthesia for knee arthroscopy is a well documented procedure with diagnostic and therapeutic role. Numerous therapeutic procedures including partial menisectomy, meniscus repair, abrasion chondroplasy, synovectomy, loose body removal can be performed safely and comfortably. Appropriate case selection, anesthetic strategy and technical expertise are the key to smooth and successful surgery.

The surgical outcome of immediate arthroscopic Bankart repair for first time anterior shoulder dislocation in young active patients.

This study evaluated the surgical outcomes of young active patients with arthroscopic Bankart repair within 1 month after first-time anterior shoulder dislocation. From July 2002-October 2004, patients presented with first-time traumatic anterior shoulder dislocation and treated with arthroscopic stabilization within 1 month of injury were retrospectively reviewed. Magnetic resonance imaging and computed tomography were performed before the operation in all cases. Cases with contralateral shoulder multidirectional instability or glenoid bone loss of more than 30% on preoperative computed tomography on the injury side were excluded. All patients were treated with arthroscopic Bankart repair, using metallic suture anchors or soft tissue bio-absorbable anchors by a same group of surgeons and followed the same rehabilitation protocol. Recurrence, instability signs, range of motion, WOSI score, Rowe score and complications were assessed. Thirty-eight patients were recruited: the average age was 21 (16-30). All patients had definite trauma history. Radiologically, all patients had Bankart/Hill-Sachs lesion. All the operations were done within 1 month after injury (6-25 days). The average hospital stay was 1.2 days (1-5 days). The average follow-up was 28 months (24-48 months). There were two cases of posttraumatic re-dislocation (5.2%). The average external rotation lag was 5 degrees (0-15) in 90 degrees shoulder abduction when compared with contralateral side. 95% of patients had excellent or good Rowe score. The average WOSI score was 83%. There was one case of transient ulnar nerve palsy and one case of superficial wound infection. This study concluded that immediate arthroscopic Bankart repair with an accelerated rehabilitation program is an effective and safe technique for treating young active patients with first-time traumatic anterior shoulder dislocation.

Arthroscopic repair of isolated type II superior labrum anterior-posterior lesion.

The effectiveness of arthroscopic repair of type II superior labrum anterior-posterior lesion (SLAP) was unclear as previous studies examined this treatment with patients of combined types of SLAP lesions. To address this research gap, we evaluated the clinical and functional outcomes of arthroscopic repair for 16 patients (mean=24.2, SD=6.5) with clinical evidence of isolated type II SLAP lesion. After having arthroscopic stabilizations with Bioknotless suture anchors (Mitek), the patients were offered post-operative rehabilitation programs (e.g., physiotherapy) for 6 months. The symptoms of SLAP lesion and the functions of the shoulder were assessed pre-operatively and 28-month post-operatively by O'Brien test, Speed test, Yergason test, and University of California at Los Angeles rating for pain and function of the shoulder. Wilcoxon Signed Ranks test and McNemar test were employed to analyze the difference between assessment in pre-operation and post-operation phases. The result showed that patients' shoulder functions improved (UCLA Shoulder Score), and symptoms of SLAP lesion reduced (O'Brien test, Speed test, and Yergason test) significantly (P<0.05). Time for returning to play with pre-injury level was in average 9.4 months (range 4-24), and no complication or recurrence was detected. We concluded that arthroscopic repair is an effective operation of type II SLAP lesion with good clinical and functional outcomes; however, athletes with high demand of overhead throwing activities are likely to take longer duration of rehabilitation to attain full recovery.