Extramuscular myofascial force transmission within the rat anterior tibial compartment: proximo‐distal differences in muscle force

Intramuscular connective tissues are continuous to extramuscular connective tissues. If force is transmitted there, differences should be present between force at proximal and distal attachments of muscles. Extensor digitorum longus (EDL), tibialis anterior (TA), and extensor hallucis longus muscles (EHL) were excited simultaneously and maximally. Only EDL length was changed, exclusively by moving the position of its proximal tendon. Distal force exerted by TA + EHL complex was not affected significantly. Proximal and distal EDL isometric force were not equal for most EDL lengths: F_prox – F_dist ranged from 0 to ≈+22.7% of F_prox at higher lengths and from 0 to ≈–24.5% at the lowest lengths. It is concluded that extramuscular connections transmit force from muscle. Significant proximo‐distal differences of EDL force remained after repeated measurements, regardless of length order, although their length dependence was altered. Measurements of both proximal and distal EDL force were highly reproducible, if EDL did not attain higher lengths than target length. After being active at high lengths, proximal and distal length–force curves were altered at low lengths but not for the highest length range. Extensor digitorum longus length–active force hysteresis was present for proximal as well as distal EDL measurements with increasing and decreasing isometric length order. Further isolating EDL removed the proximo‐distal difference for active EDL force. However a decreased difference for passive EDL force remained, which was ascribed to remaining extramuscular connective tissue linkages. It is concluded that extramuscular myofascial force transmission is an important feature of muscle that is not isolated from its surrounding tissues.     

伸肌腱腱帽解剖与异体腱帽移植的相关性实验研究

目的 探讨伸肌腱腱帽解剖与异体腱帽移植的相关性研究。方法 对6只新鲜尸手24指指伸肌腱腱帽的动力结构和静力结构进行观察,并测定了各指伸肌腱在腱帽处的滑动范围。结果 各指腱帽桡、尺侧的长度均是桡侧长于尺侧,各指伸肌腱腱帽的滑动范围在0．9－1．5cm间,示指最大,小指最小。结论 异体腱移植可恢复伸肌腱腱帽的原有结构,可避免自体肌腱移植后的肌腱移植后的肌腱下滑而影响伸指功能的恢复。     

跟腱断裂缝合修补术后并发症的分析

为了解跟腱断裂缝合修补术后并发症的情况,对我所1985年～1999年307例跟腱断裂病人的术后并发症进行了分析.307例病人共发生术后并发症41例,总并发症率为13.36%.其中较大的并发症伤口感染11例,发生率为3.58%;跟腱再断裂10例,再断率为3.26%.52例陈旧跟腱断裂病人术后发生伤口感染6例,发生率11.54%;255例急性跟腱断裂病人术后发生伤口感染5例,发生率为1.96%.跟腱断裂病人术后伤口感染率并不很低,其中陈旧跟腱断裂病人的伤口感染率显著高于急性跟腱断裂病人(p＜0.01).术后再断率(3.26%)低于文献报道的保守治疗的再断率(11.7%～17.7%).     

In-vitro reconstruction of massive rotator cuff ruptures with triceps tendon or coracoacromial ligament

The possibility of reconstructing a massive rotator cuff rupture with a free graft of the triceps tendon or the coracoacromial ligament was tested experimentally in an anatomical and biophysical cadaver investigation. After dissection of the rotator cuff, a section of the supraspinatus tendon was removed to simulate a defect in the cuff. In dissection of the grafts, a bony squama was incorporated by osteotomy. The rotator cuff was reconstructed by suturing the free grafts into the defect. In addition, the bony squama was refixed in a prepared bone groove in the greater tuberosity of the humerus. The tensile strength and the elasticity of the grafts were compared with that of the supraspinatus tendon in rupture tests. The mean value of the maximum load determined (FRm) was greatest for the triceps tendon (706.451 N), while very much lower values were found for the coracoacromial ligament (395.836 N) and the supraspinatus tendon (496.792 N). The mean value of the maximum elasticity (LAm) was lowest for the coracoacromial ligament (4.701%); the supraspinatus tendon (7.047%) and the triceps tendon (8.250%) showed very much greater elasticity. Received: 6 November 1999     

上斜肌延长术治疗Brown综合征

目的 探讨上斜肌延长手术在Brown综合征治疗中的应用.方法 对6例Brown综合征的患者施行上斜肌延长术,合并水平斜视者同时矫正水平斜视.对比观察术前术后的眼位、双眼视觉、上斜肌的功能状态及眼球运动情况.结果 术后6例患者第一眼位均正位;眼球运动明显改善,未出现上斜肌功能不足;代偿头位均消失,无A-V型斜视发生;有双眼视觉的5例,其中4例有融合功能,2例恢复立体视觉.结论 上斜肌延长手术治疗Brown综合征安全有效.     

Spontaneous rupture of the extensor pollicis longus tendon in a young goalkeeper: a case report

We report an exceptional case of an acute spontaneous rupture of the extensor pollicis longus (EPL) tendon in a 16-year-old professional goalkeeper treated by primary surgical repair. Eight weeks after surgery, full thumb motion was regained. Four months after the surgical procedure, the patient resumed playing at the same level and he had no complaint at the 12-month follow-up. The anatomical alteration of Lister's tubercle and the consequent microinstability, associated with overuse and overloading, appeared to be the cause of the EPL tendon rupture. In the present case, an end-to-end suture appeared to be a safe surgical procedure.     

Anterior cruciate ligament reconstruction with BPTB autograft, irradiated versus non-irradiated allograft: a prospective randomized clinical study

The effect of using gamma irradiation to sterilize bone-patellar tendon-bone (BPTB) allograft on the clinical outcomes of anterior cruciate ligament (ACL) reconstruction with irradiated allograft remains controversial. Our study was aimed to analyze the clinical outcomes of arthroscopic ACL reconstruction with irradiated BPTB allograft compared with non-irradiated allograft and autograft. All BPTB allografts were obtained from a single tissue bank and the irradiated allografts were sterilized with 2.5 Mrad of irradiation prior to distribution. A total of 102 patients undergoing arthroscopic ACL reconstruction were prospectively randomized consecutively into three groups. The same surgical technique was used in all operations done by the same senior surgeon. Before surgery and at the average of 31 months follow-up (range 24–47 months) patients were evaluated by the same observer according to objective and subjective clinical evaluations. Of these patients, 99 (autograft 33, non-irradiated allograft 34, irradiated allograft 32) were available for full evaluation. When compared the irradiated allograft group to non-irradiated allograft group or autograft group at 31 months follow-up by the Lachman test, ADT, pivot shift test and KT-2000 arthrometer testing, statistically significant differences were found. Most importantly, 87.8% of patients in the Auto group, 85.3% in the Non-Ir-Auto group and just only 31.3% in the Ir-Allo group had a side-to-side difference of less than 3 mm according to KT-2000. The failure rate of the ACL reconstruction with irradiated allograft (34.4%) was higher than that with autograft (6.1%) and non-irradiated allograft (8.8%). The anterior and rotational stability decreased significantly in the irradiated allograft group. According to the overall IKDC, functional, subjective evaluations and activity level testing, no statistically significant differences were found between the three groups. However, there was a trend that the functional and activity level decreased and the patients felt uncomfortable more often in the irradiated allograft group. The statistical analysis showed no significant difference between the non-irradiated allograft group and the autograft group according to the aforementioned evaluations, except that patients in the allograft group had a shorter operation time and a longer duration of postoperative fever. When comparing the postoperative duration of fever of the two allograft groups, there was also a trend that the irradiated allograft group was longer than the non-irradiated allograft group, but no significant difference was found. When the patients had a fever, the laboratory examinations of all patients were almost normal (Blood routine was normal, the values of ESR were 5 ~ 16 mm/h, CRP were 3 ~ 10 mg/l). On the basis of our study, we concluded that patients undergoing ACL reconstruction with BPTB non-irradiated allograft or autograft had similar clinical outcomes. Non-irradiated BPTB allograft is a reasonable alternative to autograft for ACL reconstruction. While the short term clinical outcomes of the ACL reconstruction with irradiated BPTB allograft were adversely affected with an increased failure rate. The less than satisfactory results led the senior authors to discontinue the use of irradiated BPTB allograft in ACL surgery and not to advocate that gamma irradiation be used as a secondary sterilizing method. Further research into alternatives to gamma irradiation is needed. Supported by Provincial Science Foundation of China (2004GG2202034).     

Reconstruction of neglected Achilles tendon rupture using the flexor hallucis tendon

Neglected ruptures of the Achilles tendon (AT) are not common and have a greater tendency to cause complications and to produce poorer functional results than fresh ruptures. Numerous surgical procedures have been described for the reconstruction of neglected AT ruptures. However, no report has been issued about an AT rupture neglected for more than 2 years. The authors reported about three patients (four tendons) with a neglected AT rupture of mean duration of 5 years, who were treated by interposed scar tissue repair combined with flexor hallucis longus tendon transfer. All patients experienced good clinical results and were satisfied with surgery. None of the authors received financial support for this study.     

Fetal dermal fibroblasts exhibit enhanced growth and collagen production in two‐ and three‐dimensional culture in comparison to adult fibroblasts

The high morbidity of tendon injuries and the poor outcomes observed following repair or replacement have stimulated interest in regenerative approaches to treatment and, in particular, the use of cell‐based analogues as alternatives to autologous and allogeneic graft repair. Given the known regenerative properties of fetal tissues, the objective of this study was to assess the biological and mechanical properties of tissue‐engineered three‐dimensional (3D) composites seeded with fetal skin cells. Dermal fibroblasts were isolated from pregnant rats and their fetuses and characterized in monolayer culture and on 3D resorbable polyester scaffolds. To determine the differences between fetal and adult fibroblasts, DNA, total protein and types I and III collagen production were measured. In addition, morphology and mechanical properties of the 3D constructs were examined. In monolayer culture, fetal fibroblasts produced significantly more types I and III collagen and displayed serum‐independent growth, while adult fibroblasts elaborated less collagen and exhibited reduced cell spreading and attachment under low‐serum conditions. In 3D culture, fetal constructs appeared more developed based on gross examination, with significantly more total DNA, total protein and normalized type I collagen production compared to adult specimens. Finally, after 35 days, fetal fibroblast‐seeded constructs possessed superior mechanical properties compared to adult samples. Taken together, these findings indicate that fetal dermal fibroblasts may be an effective source of cells for fabricating tissue equivalents to regenerate injured tendons. Copyright © 2009 John Wiley & Sons, Ltd.