评估同种异体肌腱双束重建治疗慢性肘关节后外侧旋转不稳定（posterolateral rotatory instability, PLRI）的临床结果。

回顾性分析自2016年12月至2022年12月,共有16例连续的慢性肘关节PLRI患者接受同种异体肌腱双束重建肘关节外侧韧带复合体（lateral collateral ligament complex, LCLC）。其中，男13例、女3例；年龄21~61岁，平均年龄36.4岁；创伤后韧带愈合不佳11例（11/16, 68.7%）,儿童期肱骨髁上骨折畸形愈合3例（3/16, 18.7%）,慢性劳损网球肘的医源性损伤2例（2/16, 12.5%）。所有患者均为慢性肘关节PLRI、后外侧旋转抽屉试验阳性、影像学X线应力位时肱桡关节间隙增大，急性损伤后大于1个月。所有患者接受肘关节外侧同种异体肌腱双束移植重建LCLC,肱骨及尺骨桡侧采用骨隧道固定。术后使用后外侧旋转抽屉试验评估稳定性；肘关节应力像是否出现肱桡关节间隙增大,是否出现肘关节异位骨化和创伤性关节炎神经损伤、移植物排异等并发症。末次随访记录肘关节活动度和肘关节后外侧的稳定性;采用Mayo肘关节评分（Mayo elbow performance score, MEPS），快速上肢功能评分（Quick-disabilities of the arm, shoulder and hand, Q-DASH），视觉模拟评分（visual analogue scale, VAS）对患肢功能疼痛进行主客观评分。

患者均获得随访6～36个月，平均19.2个月,未出现肘关节创伤性关节炎、异位骨化神经损伤等并发症。肘关节应力像及后外侧旋转抽屉试验术前16例阳性，术后均为阴性。MEPS评分：术前14例差（14/16 87.5%）, 2例尚可（2/16 12.5%）；术后末次随访，优13例、良2例、可1例，术后优良率93.7%，末次随访时所有患者均认为术后肘关节得到明显改善。术后末次随访MEPS、Q-DASH评分和VAS评分均较术前显著差异。肘关节活动度，术前与术后末次随访对比差异无统计学意义。

同种异体肌腱双束重建肘关节LCLC能有效的改善慢性肘关节PLRI，改善肘关节功能。

Posterolateral rotatory instability (PLRI) of the elbow is caused by damage to the lateral collateral ligament complex (LCLC). It is a common type of elbow joint instability. If the treatment is not timely or the post-treatment ligament is not well healed, the posterolateral rotation of the elbow will be chronic and unstable, seriously affecting the elbow joint function. Chronic PLRI usually occurs in the later stage of elbow trauma and also includes PLRI secondary to elbow varus deformity, severe lateral humeral epicondylitis (especially repeated corticosteroid injection), or iatrogenic injury after lateral elbow surgery. Regardless of the injury mechanism, the need to rebuild LCLC function remains challenging for orthopedic surgeons. It has been reported that several surgical techniques have been used to reconstruct LCLC, including the Yoke technique, Docking technique, single chain technique, etc. Most of them use autografts of the long palmar tendon or the lateral third of the triceps tendon at the same time. However, the allogeneic tendon and dual bundle technique for LCLC reconstruction in chronic PLRI is rarely reported.

To evaluate the clinical results of lateral ligament dual bundle reconstruction with allogeneic tendon in treating chronic posterolateral rotational instability of elbow joint.

A retrospective study was conducted from December 2016 to December 2022, in which 16 consecutive patients with chronic PLRI of the elbow underwent allogeneic tendon dual bundle reconstruction of the LCLC of the elbow joint. Clinical data includes 13 males and 3 females; Age range from 21 to 61 years old, with an average age of 36.4 years; 11 cases (11/16, 68.7%) had poor healing of ligaments after trauma, 3 cases (3/16, 18.7%) had malunion of supracondylar fractures of the humerus in childhood, and 2 cases (2/16, 12.5%) had iatrogenic injuries to the tennis elbow due to chronic strain. Inclusion criteria: All patients had chronic PLRI of the elbow joint, positive posterior lateral rotation drawer test, and increased space between the humeral and radial joints in the X-ray stress position. Patients less than 1 month after acute injury were excluded. The selected patients received dual bundle transplantation of allogeneic tendons from the lateral elbow joint to reconstruct the lateral ligament complex LCLC, and the humerus and ulna were fixed with bone tunnels on the radial side. Postoperative use of elbow joint stress imaging to evaluate posterolateral stability and posterolateral rotation drawer test to evaluate stability; Clinical efficacy and function were evaluated using the elbow joint range of motion. Mayo elbow joint function score (MEPS), quick-disabilities of the arm, shoulder, and hand (Q-DASH), and visual analog scale (VAS) were used to evaluate the functional and pain of patients.

All patients were followed up for 6-36 months, averaging 19.2 months. Elbow joint stress imaging was used to evaluate posterolateral stability, and the posterolateral rotation drawer test was used to evaluate stability. Sixteen cases were positive before, and sixteen cases were negative after surgery, and postoperative stability was significantly better. Preoperative MEPS were poor in 14 cases (14/16, 87.5%) and fair in 2 cases (2/16, 12.5%). The final test had 13 excellent cases, 2 good cases, and 1 moderate case. The excellent and good rate is 93.7%. All patients were considered to have significantly improved elbow joints at the final follow-up. The MEPS, Q-DASH, and VAS at the last follow-up significantly differed from those before surgery. There was no significant difference in elbow joint range of motion between preoperative and postoperative comparison.

The lateral ligament dual bundle reconstruction with allogeneic tendon can effectively improve chronic posterolateral rotational instability of the elbow joint and improve elbow joint function.