[Two kinds of lateral retinacular release for lateral patellar compression syndrome:a retrospective comparative study]

Objective: To compare the clinical effects of arthroscopic lateral retinacular proximal release and "L" type release for lateral patellar compression syndrome. Methods: Sixty four lateral patellar compression syndrome (LPCS) patients were recruited who had arthroscopic surgery during September 2004 to January 2019 at Department of Sports Medicine,Peking University Third Hospital by the same group of doctors and a retrospective comparative study was conducted accordingly. Among them,24 cases underwent the traditional proximal release of lateral patellar retinaculum (traditional group),including 7 males and 17 females with an age of (42.9±14.6)years(range:23 to 72 years); 40 cases were treated with novel lateral retinacular release of "L" type release revised based on the previous experiences (novel group), consisting of 12 males and 28 females with an age of (54.9±13.1) years (range:28 to 76 years).All the patients participated surveys for the visual analogue scale (VAS),Lysholm score and International Knee Documentation Committee (IKDC) knee function subjective evaluation before and after the operation. The comparison of scores within groups was performed by Wilcoxon test,and comparison between groups was performed by Mann-Whitney U test and Chi-square test. Multivariate analysis was used to evaluate the related factors affecting each score. Results: The follow-up durations of traditional group and novel group were (12.6±1.0) years (range:11.7 to 15.3 years) and (2.2±1.0)years(range:1.0 to 4.4 years) respectively. At the last follow-up,VAS(0(1.0)to 6.0(2.0),Z=-5.471,P<0.01),Lysholm score(98.0(10.0)to 48.0(40.0),Z=-5.511,P<0.01),and IKDC score(82.8(11.2)to 37.4(18.5),Z=-5.444,P<0.01) in novel group were statistically significantly improved,and the postoperative excellent rate of Lysholm score was 97.5% in general. There was no significant difference in the changes of the three scores (P>0.05) between the traditional group and the novel group. However,20.8% (5/24)patients in the traditional group reported significant weakness of the knee extension after surgery,while no such complain was received in the novel group (P<0.01).The results of univariate analysis showed that surgical method was a related factor affecting the changes of VAS before and after surgery (P<0.05).The results of multivariate analysis showed that whether or not with osteoarthritis and operation type were independent factors affecting the changes of Lysholm and IKDC scores (P<0.05). Conclusions: The long-term effect of arthroscopic lateral retinacular release for the treatment of LPCS is satisfactory. Compared with the traditional proximal release surgery,the "L" type release can effectively avoid the complication of significant weakness of the knee extension significantly.

[Surgical technique and mid-and-long curative effect analysis of primary repair of chronic Achilles tendon rupture]

Objective: To examine the surgical method and clinical outcome of primary repair of chronic Achilles tendon rupture. Methods: From March 2012 to August 2017, clinical data of 35 consecutive patients with chronic Achilles tendon rupture who were treated with primary repair by the same doctor at Department of Sports Medicine, Peking University Third Hospital were retrospectively analyzed.There were 29 males and 6 females with age of (41.0±9.3)years(range:29-65 years), the follow-up period was (45.6±17.2) months(range:17-82 months). All the patients had unilateral tendon rupture with 22 cases on the left and 13 cases on the right.The preoperative and postoperative Visual Analogue Scale(VAS), American Orthopaedic Foot and Ankle Society Ankle-Hindfoot Score(AOFAS), the Victorian Institute of Sport Assessment-Achilles(VISA-A), the Achilles tendon Total Rupture Score(ATRS)and the Tegner Activity Score of patients were collected and compared by paired-t test. Results: Among 47 patients with chronic Achilles tendon rupture, 35 patients were followed up for (45.6 ± 17.2)months(range: 17-28 months). No serious postoperative complications such as infection or nerve damage and rerupture outcomes were reported. At the last follow-up,the VAS decreased from 1.0(2.0) (M(Q(R))) preoperative to 0.0(0.8)(Z=-3.586, P=0.00), AOFAS increased from 64.3±12.5 to 97.0±5.0(t=-14.359,P<0.001), VISA-A increased from 51.3± 9.8 to 87.8±18.0(t=- 17.656, P=0.00), Tegner increased from 0.9±0.3 to 4.6±1.7(t=- 12.524, P=0.00)and ATRS increased from 40.0±3.5 to 97.9±3.9(t=-64.133,P=0.00). Twenty-eight patients (80.0%) had returned to their preinjury activity levels, and 7 patients (20.0%) no longer participate in recreational sports. According to Arner-Lindholm curative effect evaluation criteria, 32 cases(91.4%)gained the excellent results, 1 case(2.9%) of good and 2 cases(5.7%) bad, and the percentage of the cases with the excellent or good results was 94.3%. All except 2 patients with bad results could perform a single-limb heel rise painlessly. Conclusions: Primary repair is an efficient approach for chronic Achilles tendon rupture. The mid-and-long curative effect is satisfactory and stable.Compared with other surgical techniques, operation is relatively simple and economical. The primary repair is considerably safe, with few serious complications such as infection or nerve damage and reruptures.

[Anatomical and finite element analysis of anterior cruciate ligament reconstruction within biomechanical insertion]

OBJECTIVE

To provide new concepts of anterior cruciate ligament (ACL) reconstruction by anatomical gross observation of ACL tibial insertion and finite element analysis of distribution of ACL mechanical insertion.

METHODS

In the anatomical study, ten fresh adult cadaveric knees were dissected, including 6 males and 4 females, all knees were generally observed through standard medial parapatellar approaches, paying attention to the close anatomical relationship of tibial insertion and anterior horn of lateral meniscus, and ACL was exposed and gradually removed from the inside. The shape of tibial insertion of ACL was observed and recorded, and anterior-posterior diameters and left-right diameters of tibial insertion were measured with vernier caliper. For the study of finite element analysis, three-dimensional thin-layer magnetic resonance imaging of normal knee joint was used to establish knee joint model. Three-dimensional reconstruction software MIMICS and finite element analysis software ANSYS were used to establish knee joint model, subsequently, clinical physical examination Lachman test and pivot-shift test were simulated to observe the force distribution of ACL tibial insertion and femoral insertion.

RESULTS

The ACL tibial mechanical insertion was rather flat and long similar as an arc shape without a clear separation between anterior medial bundle (AMB) and posterolateral bundle (PLB) in gross observation. The dense fibers lies belonged to the medial intercondylar ridge and ended up anterior with the osseous landmark of anterior ridge. Its average anterior-posterior diameter was (13.8±2.0) mm, the average left-right diameter of midsubstance was (5.3±0.6) mm, and the average left-right diameter of anterior margin was (11.5±1.2) mm. The finite element analysis showed that distribution on the femoral side was oval shape mainly below the residents' ridge, while the tibial side was rather flat mainly along the medial intercondylar ridge, which was consistent with the anatomical observation. The biomechanical characteristics of ACL attachments were verified theoretically.

CONCLUSION

Anatomical study and finite element analysis have confirmed the flat arc shape of ACL tibial insertion. The ideal reconstruction technique of ACL should be based on its biomechanical insertion. Based on anatomical study and biomechanical analysis, we have proposed the idea of ACL biomechanical insertion reconstruction (BIR) and established a surgical model with oval femoral tunnel and rounded-rectangle tibial tunnel.

Runx2 overexpression enhances osteoblastic differentiation and mineralization in adipose--derived stem cells in vitro and in vivo

Like bone marrow stromal cells, adipose tissue-derived stem cells (ADSCs) possess multilineage potential, a capacity for self-renewal and long-term viability. To confirm whether ADSCs represent a promising source of cells for gene-enhanced bone tissue-engineering, the osteogenic potential of ADSCs under the control of certain osteoinductive genes has been evaluated. Runx2, a transcription factor at the downstream end of bone morphogenetic protein (BMP) signaling pathways, is essential for osteoblast differentiation and bone formation. In this study we used adenovirus vector to deliver Runx2 to ADSCs and then examined the enhancement of osteogenic activity. Overexpression of Runx2 inhibited adipogenesis, as demonstrated by suppression of LPL and PPARgamma expression at the mRNA level and reduced lipid droplet formation. Moreover, ADSCs transduced with Ad-Runx2 underwent rapid and marked osteoblast differentiation as determined by osteoblastic gene expression, alkaline phosphatase activity and mineral deposition. Additionally, histological examination revealed that implantation of Runx2 modified ADSCs could induce mineral deposition and bone-like tissue formation in vivo. These results confirmed, firstly, the ability of Runx2 to promote osteogenesis and cell differentiation and, secondly, the competence of ADSCs as target cells for bone tissue engineering. Our work demonstrates a potential new approach for bone repair using Runx2-modified ADSCs for bone tissue engineering.

[Diagnosis and treatment of closed complete rupture of patellar tendon. Analysis of 11 cases]

Eleven cases of closed complete rupture of patellar tendon (4 neglected ruptures and 7 fresh ruptures) were treated. Seven of them were treated in extension for 6-8 weeks after operation, 1 was immobilized with patellar traction in the early stage on bed, and 3 were mobilized and assisted with movable brace standing and walking through the body weigh on the knee in the early stage after operation. The aim was to promote the functional recovery of the knee joint. The mechanism of injury, clinical diagnosis, treatment and rehabilitation of closed rupture of patellar tendon were discussed in combination with clinical experience. And the suggestion of movement and active recovery in the early stage after patellar tendon surgery was put forward.

[Contractile function of the gallbladder after gastrectomy]

Gallbladder contractile function was observed by B-mode ultrasonography on patients with radical gastrectomy for gastric carcinoma (20 cases), with subtotal gastrectomy for peptic ulcer (36 cases), and with highly selective vagotomy (7 cases). Thirty-one preoperative patients with peptic ulcer were used as control. It was found that within one month after radical or subtotal gastrectomy the average area and the volume of the gallbladder became much larger than that found in control group. The empty rate of the gallbladder was found decreased and the remainder bile increased. Early stage gallstones were found in two cases 11 and 13 months after gastrectomy. The inner diameter of the common bile duct was increased after radical gastrectomy. No definite relationship was found between gallbladder contractile disfunction and the mode of gastroenterostomy. It was also found that highly selective vagotomy had only slight influence on the biliary tract. These results suggest that gastrectomy has significant influence on the function of biliary tract and plays an important role in the formation of gallstones.