Measurement of tension of tendon tissue based on electrical impedance

The objective of this study was to examine whether the tension of tendon tissue could be measured using electrical impedance and, if so, whether the errors in measurement of the initial tension of a reconstructed anterior cruciate ligament obtained using electrical impedance were small enough to allow its use in clinical practice. The patella–patellar tendon–tibia complex from 35 pig knees was dissected. The relationship between the impedance of the patellar tendon and the traction stress loaded on the patellar tendon, and the repeatability of stress–impedance curves was examined in 15 knees. The relationship between impedance and strain was examined in 5, the influence of the tendon traction direction on tendon impedance was examined in 5, and the influence of the axial torsional deformation of the tendon on tendon impedance was examined in 5. Moreover, the relationship between the initial tension of a reconstructed ligament measured using electrical impedance and the load applied to the reconstructed ligament was examined in the remaining 5 knees. The change in electrical impedance of the patellar tendon due to traction was mostly caused by the strain of the tendon. The mean repeatability was 9.1%, the mean error due to differences in traction direction was 9.7%, and the mean error due to axial torsional deformation was 6.8%. There was a very strong correlation between the tension of the reconstructed ligament measured using electrical impedance and the force applied to the reconstructed ligament. Therefore, electrical impedance can be used to measure tendon tension, and it serves to measure the initial tension of a reconstructed ligament consisting of tendon tissue.     

Augmentation of anterior cruciate ligament reconstruction in dogs with prostheses of different stiffnesses

The purpose of this study was to investigate the biological and biomechanical properties of anterior cruciate ligament (ACL) reconstruction augmented with Dacron prostheses of three different stiffnesses. The ACLs of 36 adult mongrel dogs were removed and the ligament was reconstructed. In 18 dogs, one knee was reconstructed with patellar tendon alone, and the contralateral knee with Dacron augmented patellar tendon. In the remaining 18 dogs, reconstruction was with Dacron augmented patellar tendon with Dacron alone being used for the contralateral control knee. Death was 3 months after surgery, and the reconstructions were examined biologically and biomechanically. The mechanical data were compared with immediate postoperative data obtained from 45 reconstructed fresh cadaveric knees. Tensile testing demonstrated that an increase in failure load was found when the implanted patellar tendon graft was compared with the cadaveric reconstruction. The strength of the Dacron augmented reconstruction showed little change while the Dacron alone graft decreased in strength during the period of implantation. No clear difference was found between the performance of augmentation devices of different stiffnesses. Microangiography showed that grafts were totally revascularized in patellar tendon alone, but not well revascularized in Dacron augmented patellar tendon and Dacron alone reconstruction. The presence of the Dacron appeared to have an adverse effect on revascularization.     

Extensive post-traumatic ossification of the patellar tendon. A report of two cases

Two men, aged 21 and 50 years, were seen with ossification of the patellar tendon after injury to the knee in adolescence. They complained of pain and had patella alta. Large bony masses were excised from below the affected patellae. The patellar tendon was then reconstructed using a Leeds-Keio ligament. The results at six and ten years, respectively, were good, with neither patient having pain or an extension lag.     

Arthroscopically assisted combined anterior and posterior cruciate ligament reconstruction

This article presents the minimum 2-year results (range, 24 to 48 months) of 20 arthroscopically assisted combined anterior cruciate ligament/posterior cruciate ligament (ACL/PCL) reconstructions, evaluated preoperatively and postoperatively using the Tegner, Lysholm, and Hospital for Special Surgery knee ligament rating scales, and the KT 1000 knee ligament arthrometer (Medmetric Corp, San Diego, CA). There were 16 men or boys, 4 women or girls; 9 right, 11 left; 10 acute, and 10 chronic knee injuries. Ligament injuries included 1 ACL/PCL tear, 2 ACL/PCL/medial collateral ligament (MCL)/posterior lateral corner tears, 7 ACL/PCL/MCL tears, and 10 ACL/PCL/posterior lateral corner tears. ACLs were reconstructed using autograft or allograft patellar tendons. PCLs were reconstructed using allograft Achilles tendon, or autograft patellar tendon. MCL tears were successfully treated with bracing. Posterior lateral instability was successfully treated with long head of the biceps femoris tendon tenodesis. Teguer, Lysholm, and Hospital for Special Surgery knee ligament rating scales significantly improved preoperatively to postoperatively (P = .0001). Corrected anterior KT 1000 measurements improved from preoperative to postoperative status (P = .0078).     

关节镜辅助下小切口重建内侧髌股韧带治疗创伤性复发性髌骨脱位

目的探讨关节镜辅助下小切口同种异体肌腱重建内侧髌股韧带(MPFL)治疗创伤性复发性髌骨脱位的临床效果。方法回顾性分析自2006年1月～2010年4月共收治28例创伤性复发性髌骨脱位,所有患者在第一次脱位均为膝关节外伤所致,伤后患膝明显肿胀及髌骨脱位-复位感,此后出现髌骨脱位3次以上者。手术方法:先行关节镜检查,髌骨外侧支持带紧张者行松解术,关节镜监视下调整MFPL的张力并于其解剖止点以同种异体肌腱重建MFPL,术后接受正规功能康复锻炼。结果术后平均随访26个月(12～36个月)。重建术后无髌骨再次脱位发生,髌股关节稳定。术前、术后均采用Lysholm和Kujala膝关节评分标准,手术前后评分差异有统计学意义(P<0.05)。结论选择适当的病例,重建内侧髌股韧带是治疗创伤性复发性髌骨脱位的有效方法。     

Nerve regeneration during patellar tendon autograft remodelling after anterior cruciate ligament reconstruction: An experimental and clinical study

The innervation of the rat and human anterior cruciate ligament, patellar tendon, and patellar tendon autograft after reconstruction of the anterior cruciate ligament was investigated by immunohistochemical and histological methods. A rat model of reconstruction with patellar tendon autograft was evaluated during active graft remodelling (2–16 weeks) and compared with normal ligament and tendon. The knees of 10 patients who had undergone reconstruction with patellar tendon autograft were examined 5–37 months postoperatively (remodelling fully completed) with arthroscopy and biopsy. As a control, biopsies from normal ligament and tendon were obtained from four patients. Nerve fibers were identified using antisera for protein gene product 9.5, a general neural marker. Neuronal regeneration was assessed by the expression of growth-associated protein 43/B-50. The sensory type of innervation was characterized by assessing the distribution of nerves containing the sensory neuropeptides calcitonin gene related peptide and substance P. Immunoreactivity for all neural markers was found in both rat and human anterior cruciate ligament and patellar tendon. Two weeks after reconstruction, the rat autograft was acellular and no innervation could be identified. After 4 weeks, the grafts were viable, and immunoreactivity for protein gene product 9.5, growth associated protein 43/B-50, and calcitonin gene-related peptide was found until the 16th week postoperatively. Immunoreactivity for substance P was found in rat autografts at 4 weeks postoperatively only. All biopsies of human patellar tendon autograft showed signs of the remodelling process being fully completed, with revascularization and a sinusoidal collagen pattern with fibroblast repopulation. Neuropeptide immunoreactivity, however, was not found. The presence of immunoreactivity to sensory neuropeptides in the anterior cruciate ligament and patellar tendon may indicate a nociceptive and neuromodulatory function of these structures. The expression of sensory neuropeptides in the rat patellar tendon autograft suggests a possible involvement of sensory innervation during healing of the graft.     

Simultaneous ipsilateral ruptures of the anterior cruciate ligament and patellar tendon: a case report

The simultaneous diagnosis of ipsilateral patellar tendon rupture and anterior cruciate ligament tear is rare. Surgical repair is complicated by different rehabilitation regimens as well as anterior cruciate ligament graft choices. We present a case where at the same operative setting, the patellar tendon was repaired, and the anterior cruciate ligament reconstructed with autologous hamstring graft.     

Patellar tendon avulsion after reconstruction of the anterior cruciate ligament

We report a case of rupture of a reconstructed anterior cruciate ligament (ACL) combined with avulsion of the inferior patellar ligament. The two lesions were repaired during one operation using the quadriceps tendon as a graft for the damaged ACL.     

Arthroscopic transtibial single-bundle posterior cruciate ligament reconstruction using patellar tendon graft compared with hamstring tendon graft

Purpose

The purpose of this study was to compare the outcomes of arthroscopic transtibial single-bundle posterior cruciate ligament reconstruction using autologous patellar tendon and hamstring tendon grafts.

Methods

From 1998 to 2007, 59 patients with symptomatic isolated posterior cruciate ligament injury were included in this retrospective study. Twenty-five knees were reconstructed using bone-patellar tendon-bone graft, and 34 knees were reconstructed using hamstring graft. In both groups, surgical techniques were similar, except material of fixation screws. Patients were evaluated pre-operatively and post-operatively at the latest follow-up with several parameters, including symptoms, physical examination, outcome satisfaction, functional scores, radiography and complications.

Results

Average follow-up period was 51.6 months in patellar tendon group and 51.1 months in hamstring tendon group. Significantly more kneeling pain (32 vs. 3 %), squatting pain (24 vs. 3 %), anterior knee pain (36 vs. 3 %), posterior drawer laxity and osteoarthritic change were shown in patellar tendon group than in hamstring tendon group post-operatively. No significant differences were found in other parameters between both groups.

Conclusions

Several shortcomings, including anterior knee pain, squatting pain, kneeling pain and osteoarthritic change, have to be concerned when using patellar tendon autograft. In conclusion, hamstring tendon autograft may be a better choice for transtibial tunnel PCL reconstruction.     

Akagi胫骨前后轴在全膝关节置换术中的定位作用

目的 分析膝关节CT片上Akagi胫骨前后轴与髌腱中内1/3点、髌腱内侧缘等解剖标志的相互关系,确定全膝关节置换术中胫骨假体旋转定位的参照轴线.方法 对40名青年健康志愿者行膝关节伸直中立位CT检查.Akagi胫骨前后轴定义为CT片上垂直于外科经上髁轴且经过后十字韧带中点的直线.于胫骨平台平而及预定截骨平面标记胫骨前后轴及其与髌腱相交点、后十字韧带中点与髌腱内侧缘及髌腱中内1/3点连线,分别测量胫骨前后轴与髌腱相交点内侧髌腱占髌腱总宽度的比例、后十字韧带中点与髌腱内侧缘及髌腱中内1/3点连线同胫骨前后轴之间的夹角.结果 在胫骨平台平面,胫骨前后轴经过髌腱内侧缘外侧10.1%±8.3%处;在预定截骨平面,胫骨前后轴经过髌腱内侧缘外侧0.2%±10.0%处.在预定截骨平面,后十字韧带中点与髌腱内侧缘连线和胫骨前后轴的夹角为0.1°±2.7°,后十字韧带中点与髌腱中内1/3点连线和胫骨前后轴的夹角为10.3°±3.6°.结论 全膝关节置换术中,当以胫骨结节中内1/3点为标准行胫骨假体旋转放置时,有导致胫骨假体相对于股骨假体过度外旋的可能.后十字韧带中点与髌腱内侧缘连线几乎与Akagi胫骨前后轴重叠,可以作为全膝关节置换术中胫骨假体旋转定位的参照轴线.     

A method of repair for quadriceps tendon or patellar ligament (tendon) ruptures without cast immobilization. Preliminary report

The quadriceps tendon and patellar tendon (ligament) were repaired with a Dacron vascular graft used as a tension suture material. In cases of quadriceps tendon ruptures, the Dacron graft is passed transversely through the patellar ligament just below the patella and crossed transversely at the level of the musculotendinous junction with two loops applying tension to the tendon, which brings the tendon ends together by creating a solid structure. In cases of patellar ligament ruptures, the Dacron graft is passed through a hole in the tibia posteriorly to the tibial tuberosity instead of through the patellar ligament below the patella. This technique enables early mobilization on the first day after surgery. The technique was first tested on six dogs with severed quadriceps tendons and patellar ligaments that were repaired with this suture method. All of the animals recovered from surgery and walked and ran normally on the repaired legs within 27 days and with only mild limping after 17 days. The technique was then used on six patients, four with complete quadriceps tendon rupture and two with complete tear (avulsion) of the patellar ligament (tendon). In all of the patients, excellent surgical results were obtained and leg immobilization was virtually eliminated. Physical therapy was prescribed the first day after surgery. The rehabilitation period was significantly reduced.     

自体中1／3髌韧带重建前十字韧带术后膝关节内并发症的探讨

目的探讨应用自体中1/3髌韧带移植重建前十字韧带术后膝关节内有关的并发症及其发病机制。方法1994年1月～1997年11月 ,对18例前十字韧带断裂的患者采用关节镜或小切口关节切开术 ,完成自体中1/3髌韧带移植重建前十字韧带。术后平均随访2年 ,对所有病例进行临床检查 ,确定膝关节疼痛部位 ,检查膝关节活动度及稳定性 ,并利用膝关节屈曲90°的侧位X线片测量髌韧带长度。结果随访18例患者 ,17例术后膝关节存在触发性或功能性疼痛 ,膝关节疼痛常位于髌股关节、髌骨下极、髌韧带供区及胫骨结节部位。8例患者术后患膝活动度有不同程度受限。6例患者髌韧带发生不同程度的短缩 ,平均短缩2.8mm。4例患者髌股关节间隙变窄。两种术式以上并发症的发生率及严重程度差异无显著性意义。结论应用自体中1/3髌韧带重建前十字韧带不仅应注意疼痛等并发症的发生 ,还应关注髌韧带供区及髌股关节并发症的发生 ,重视其发病的病理基础。髌韧带中1/3缺损可引起髌韧带短缩及髌股关节退变。     

Mechanical properties of PDS-augmented patellar tendon transplants in reconstruction of the anterior cruciate ligament]

In 25 sheep the anterior cruciate ligament (ACL) was reconstructed after resection. Twelve modified "Jones procedures" were performed (transplantation of the central third of the patellar tendon with an initial load of 50 N) and 13 polydioxanone (PDS) augmentations. In 15 cases the ACL was resected from the right knee. Twenty-one sheep survived for 1 year and were then evaluated. Loss of the ACL leads to instable joints in this experiment. Within the first 6 months anterior translation occurs; after 1 year subluxations can be seen on the X-ray films. Macroscopical signs of extensive arthrosis were seen in the femorotibial and femoropatellar joints; the menisci were totally destroyed. Macroscopically strong ligaments were seen 1 year after PDS-augmented reconstruction as well as after transplantation of the patellar tendon with an initial load of 50 N. There was no difference between the two groups. The mechanical strength reached 54% of the maximum load of a control group in the Jones reconstructions and 61% after additional augmentation with a 2-mm biodegradable PDS cord. There was no statistically significant difference. Both methods are suitable for reconstruction of the ACL; the patellar tendon replaces the ACL very well.     

关节镜下膝前交叉韧带重建术疗效分析

目的：探讨自体中1／3骨－髌腱－骨（B－PT－B）重建前交叉韧带（ACL）的临床效果。方法：1996年9月－2000年10月对13例膝ACL损伤，其中男9例，女4例，年龄23－45岁。均采用关节镜下自体中1／3B－PT－B重建ACL，挤压螺钉固定，治疗CAL损伤后关节不稳定，术前抽屉试验13例均为阳性，轴移试验4例阳性，Lachman试验7例阳性，术后获随访5－25个月，平均15个月。结果：术后屉试验，轴移试验和Lachman试验均转阴性。按照Bosaotta的术后临床指标评价方法，优9例，良3例，可1例，所有患者均感膝关节稳定性明显改善。结论：关节镜下自体中1／3B－PT－B重建ACL损伤疗效显著。     

Regeneration process of mechanoreceptors in the reconstructed anterior cruciate ligament

We performed reconstructive surgery on the anterior cruciate ligament (ACL) of the rabbit using a free bone-patellar tendon-bone (BTB) graft and evaluated nerve regeneration in the graft. The right ACL of 15 Japanese white rabbits was resected and reconstructed using a BTB graft. The BTB and ACL from the contralateral knee served as controls. The graft and control BTB were collected at 2, 4, and 8 weeks after the operation. We measured the number of mechanoreceptors in the ligaments using a modified gold chloride method. In the control patellar tendon, mechanoreceptors were present in all the samples. At 2 weeks after the operation, mechanoreceptors were not observed in the reconstructed ligaments. They were observed at 4 weeks but in lower numbers than in the control knees. At 8 weeks, the total number of mechanoreceptors did not differ significantly in the reconstructed and control tendons. The appearance of mechanoreceptors in the graft between 2 and 4 weeks postoperatively suggests that regeneration of mechanoreceptors occurred during this time period. At 4 and 8 weeks postoperatively, there was no significant difference in the number of mechanoreceptors between the intra-articular portion of grafted tendon and the contralateral ACL. The further increase between 4 and 8 weeks to control levels suggests that this regeneration may restore mechanoreceptors in BTB grafts to normal levels.     

Arthroscopically assisted combined posterior cruciate ligament/posterior lateral complex reconstruction

This article presents the minimum 2-year results (range, 24 to 54 months) of 21 arthroscopically assisted posterior cruciate ligament/posterior lateral complex (PCL/PLC) reconstructions, evaluated preoperatively and postoperatively using the Tegner, Lysholm, and Hospital for Special Surgery knee ligament rating scales, and the KT 1000 knee ligament arthrometer (Medmetric Corp., San Diego, CA, U.S.A.). There were 15 male and 6 female patients; 6 right and 15 left; and 10 acute and 11 chronic knee injuries. All injuries were PCL/PLC knee ligament injuries. PCLs were reconstructed using allograft Achilles tendon, or autograft patellar tendon. Posterior lateral instability was successfully treated with long head of biceps femoris tendon tenodesis. Tegner, Lysholm, and Hospital for Special Surgery knee ligament rating scales significantly improved preoperatively to postoperatively (P = .0001). PCL screen and corrected posterior KT 1,000 measurements improved from preoperative to postoperative status (P = .0009, and P = .0096, respectively).     

Nutrition of cruciate ligament reconstruction by diffusion: Collagen synthesis studied in rabbits

The reconstructed anterior cruciate ligament was studied in the rabbit using the medial third of the patellar tendon. Tritiated proline, 100 μCi/kg body weight, was injected intra-articularly to insure detection of the metabolic conversion product ³H-hydroxyproline in the avascular graft. During the immediate postoperative period, nutrients were found to derive from the synovial fluid through a process of diffusion, demonstrating that synovial nutrition occurs prior to revascularization of the graft.     

Nutrition of cruciate ligament reconstruction by diffusion. Collagen synthesis studied in rabbits

The reconstructed anterior cruciate ligament was studied in the rabbit using the medial third of the patellar tendon. Tritiated proline, 100 microCi/kg body weight, was injected intra-articularly to insure detection of the metabolic conversion product 3H-hydroxyproline in the avascular graft. During the immediate postoperative period, nutrients were found to derive from the synovial fluid through a process of diffusion, demonstrating that synovial nutrition occurs prior to revascularization of the graft.     

Reconstruction of medial patellofemoral ligament for chronic patellar instability

Background:

Disruption of the capsule, medial patellar retinaculum, and/or vastus medialis obliqus has been associated with recurrent patellar instability. Biomechanical studies have shown that the medial patellofemoral ligament (MPFL) is the main restraint against lateral patella displacement and reconstruction of the MPFL has become an accepted surgical technique to restore patellofemoral stability in patients having recurrent patellar dislocation. We report a prospective series of patients of chronic patellar instability treated by reconstruction of medial patellofemoral ligament.

Materials and Methods:

Twelve patients (15 knees) with recurrent dislocation of patella, were operated between January 2006 and December 2008. All patients had generalised ligament laxity with none had severe grade of patella alta or trochlear dysplasia. The MPFL was reconstructed with doubled semitendinosus tendon. Patients were followed up with subjective criteria, patellar inclination angle, and Kujala score.

Results:

The mean duration of followup after the operative procedures was an average of 42 months (range 24–60 months) 10 knees showed excellent results, 3 knees gave good results, and 2 knees had a fair result. The average patellar inclination angle decreased from 34.3° to 18.6°. The average preoperative Kujala functional score was 44.8 and the average postoperative score was 91.9.

Conclusion:

MPFL reconstruction using the semitendinosus tendon gives good results in patients with chronic patellar instability without predisposing factors like severe patella alta and high-grade trochlear dysplasia, and for revision cases.     

髌腱复合体重建创伤性前后交叉韧带

目的：为了评价髌腱复合体(带骨块的髌韧带，即骨—髌膜—骨)对前后交叉韧带断裂后重建的手术疗效。方法：1995—2001年，收治32例前后交叉韧带损伤的患者给予髌腱复合体重建术。结果：所有病人患膝关节稳定性明显增强，术后抽屉试验全部阴性。结论：带骨块的髌韧带具有强抗牵拉力，固定可靠，等长重建，功能改善明显等优点。髌膜复合体是理想的前后交叉韧带替代材料。