Outcome and experience of arthroscopic lateral retinacular release combined with lateral patelloplasty in the management of excessive lateral pressure syndrome

Patellar malalignment: A common disorder associated with knee pain

Pain-associated knee joint disorders are common in daily life. Practically, knee pain should be divided into the origin from the isolated tibiofemoral (TF), isolated patellofemoral (PF) joint, or a combination thereof. The TF joint controls the actions of level walking, while the PF joint controls knee flexion-extension. Owing to its sufficient inherent stability, non-traumatic disorders of the isolated TF joint in young individuals are uncommon. In contrast, because of its insufficient inherent stability, non-traumatic disorders of the isolated PF joint are common in young individuals. Patellar malalignment (PM) associated with knee pain is common in all age groups, and the most common predisposing factor is imbalanced peripatellar soft-tissue tension. The outward forces acting on the patella are caused by pulling from the quadriceps femoris during knee flexion to extension (manifested by the quadriceps angle [Q-angle]), and sliding backward of the iliotibial band (ITB) during knee extension to flexion. Once the muscle power of the vastus medialis (especially the vastus medialis obliquus [VMO]) decreases, which lowers the counteracting effect against outward forces, the patella displaces or rotates laterally. The reduced contact surface between the patella and the femoral condyle significantly increases the compressive pressure and injures the articular cartilage. Subsequently, progressive PF degeneration occurs. Although other factors may also cause PM, they are relatively uncommon. In principle, nonsurgical treatment of PM should be considered first, while surgical treatment should follow established indications. Some nonsurgical techniques are currently widely used that feature high satisfaction rates. Surgical techniques are continuously being developed, and their success rates have gradually improved. This study aimed to review the current literature for relevant studies and report related publications of the author's institution to emphasize the universality and importance of PM management. Conceptually, simply focusing on problems of the TF joint cannot treat all knee disorders.

Imrecoxib versus celecoxib as postoperative analgesia for patients receiving arthroscopic knee surgery: a randomized, controlled, non-inferiority study

OBJECTIVE

Imrecoxib is a novel cyclooxygenase-2 inhibitor independently developed in China, which exhibits a good efficacy and tolerance in orthopedic disorders. The current study aimed to further compare its efficacy and safety with celecoxib as postoperative analgesia in arthroscopic knee surgery (AKS).

METHODS

Patients receiving AKS were enrolled and randomly assigned to imrecoxib (n = 64) and celecoxib (n = 62) group to receive analgesia for 72 h after surgery. Pain at rest and movement, pethidine consumption, patient's satisfaction, Lysholm score, and adverse events were assessed after AKS. Meanwhile the upper limit of 95% CI of pain-score mean difference (MD) between imrecoxib and celecoxib was calculated, then, the non-inferiority was defined if the all-time-point upper limits of 95% CI less than 1.

RESULTS

Imrecoxib was non-inferior to celecoxib for alleviating pain at rest (upper limit of 95% CI of MD ranging from 0.443 to 0.782, all time-point values less than 1); as well as for attenuating pain at movement (upper limit of 95% CI of MD ranging from 0.398 to 0.582, all time-point values less than 1). Moreover, rescue analgesia rate (P = 0.583), pethidine consumption (P = 0.454), patient's satisfaction at 72 h (P = 0.408), and Lysholm score at M3 (P = 0.776) were of no difference between imrecoxib group and celecoxib group. Additionally, the main adverse events in two groups were nausea (P = 0.425), constipation (P = 1.000), vomiting (P = 0.715), headache (P = 1.000), and dizziness (P = 0.667), which were mild and manageable.

CONCLUSION

Imrecoxib is non-inferior to celecoxib in postoperative analgesia and exhibits an acceptable tolerance in patients undergoing AKS.

Effect of Lateral Retinacular Release on Medial Patellofemoral Ligament Reconstruction

Background:

When performing a medial patellofemoral ligament (MPFL) reconstruction, surgeons may place the MPFL graft under higher than anatomic tension to minimize the chance of recurrent instability.

Purpose:

To investigate whether a lateral retinacular release (LRR) significantly decreases patellofemoral contact pressures after an overtensioned (OT) MPFL reconstruction.

Study Design:

Controlled laboratory study.

Methods:

Mean and peak pressure across the patellofemoral joint at 30°, 45°, and 60° of flexion was assessed in 14 cadaveric knee specimens with intact MPFL, transected MPFL, reconstructed MPFL with graft OT, and OT MPFL with LRR. The Wilcoxon signed rank test was used to determine differences across states, with W and C values calculated when possible.

Results:

Mean pressure decreased significantly after MPFL transection compared with intact at 30° (456.9 ± 116.8 vs 410.9 ± 109.4 N, P = .006, W < 7) and 45° (404.9 ± 91.7 vs 369.4 ± 85.3 N, P = .005, W < 5) and increased significantly from intact to OT graft at 30° (456.9 ± 116.8 vs 563.0 ± 11.2 N, P = .003, W < 7), 45° (404.9 ± 91.7 vs 481.4 ± 14.8 N, P = .005, W < 5), and 60° (272.9 ± 139.0 vs 367.0 ± 53.7 N, P = .007, W < 3). Peak pressure increased significantly between intact and OT graft at 30° (1364.0 ± 478.2 vs 2094.4 ± 619.8 N, P = .002, W < 9), 45° (1224.7 ± 491.5 vs 1676.7 ± 779.1 N, P = .005, W < 5), and 60° (1117.7 ± 566.8 vs 1604.2 ± 772.9 N, W < 3). In knees with significantly increased mean pressure after overtensioning, mean pressure increased by 23.3% (11/14 knees) at 30°, 18.3% (10/14 knees) at 45°, and 35.0% (10/14 knees) at 60°. Peak pressure increased significantly by 35.3% (30°), 25.2% (45°), and 29.3% (60°). A significant decrease in mean pressure, toward but not to baseline, was observed between the OT and LRR states at 30° (563.0 ± 11.2 vs 501.5 ± 9.3 N, W < 7) and 60° (367.0 ± 53.7 vs 302.0 ± 13.8 N, W < 5) and a decrease in peak pressure at 30° (2094.4 ± 619.8 vs 1886.5 ± 655.3 N; W < 9).

Conclusion:

LRR led to a statistically significant decrease in pressure across the patellofemoral joint in knees that demonstrated increased contact pressures after an OT MPFL graft.

Clinical Relevance:

LRR after an MPFL reconstruction in which the MPFL graft has been OT may help reduce patellofemoral contact pressures at the time of surgery.