Dacron augmentation in anterior cruciate ligament reconstruction in dogs

Substitution of the central third of the patellar tendon for the deficient anterior cruciate ligament was performed in 12 dogs (24 knees). In one-half of the knees the patellar tendon grafts were "augmented" with a 4-mm woven Dacron graft. It was hypothesized that Dacron augmentation would protect the patellar tendon graft during its revascularization stages. This was not the case, however. Only once did a Dacron ligament graft demonstrate superiority over the nonaugmented graft; indeed, five of the augmented grafts performed significantly worse.     

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.     

前交叉韧带重建术后关节镜下股部肌力测量

目的　观察自体中1/3 骨-髌韧带-骨为供区,重建前交叉韧带后对股部肌力的影响。方法　自体中1/3 骨-髌韧带-骨移植重建前交叉韧带术后1年,关节镜下再视观察到无膝内紊乱的患者23 例;男9 例,女14 例。平均年龄为20.8岁。所有患者在关节镜再视术前使用MyretRZ-450型CybexⅡ等速肌肉功能测试器,对患侧和健侧进行股四头肌和腘绳肌的等长(60°和90°)和等速(60°/s和180°/s)肌力测定。结果　自体中1/3骨-髌韧带-骨做为供区,重建前交叉韧带之侧别的股四头肌肌力比健侧的股四头肌肌力明显降低(P< 0.01)。而获取自体中1/3 骨-髌韧带-骨移植后,对腘绳肌肌力则无影响(P> 0.05)。结论　获取自体中1/3 骨-髌韧带-骨移植重建前交叉韧带后,可严重降低股四头肌肌力     

The morphological effects of synthetic augmentation in posterior cruciate ligament reconstruction

The treatment of posterior cruciate ligament (PCL) injuries remains controversial. Due to various problems, PCL reconstruction has not consistently produced the knee stability desired. Biological graft tissue undergoes a remarkable healing process comprising different phases. The strength of autogenous graft material decreases soon after operation. During this early healing phase synthetic augmentation could protect the graft tissue from overloading or overstretching, supporting the tissue revitalization and remodeling process. In order to evaluate the morphological effects of the ligament augmentation device (LAD) on a free patellar tendon autograft in PCL reconstruction, a comparative study in sheep was conducted. In 24 mature sheep, the PCL was replaced with either a patellar tendon autograft alone or a patellar tendon autograft augmented by the LAD. The LAD was fixed at both ends. After the operation the animals were not immobilized. Tibial fixation was released 8 weeks postoperation. The autografts of both groups were histologically evaluated after 2, 6, 16, 26, 52, and 104 weeks. In addition to necrotic and degenerative alterations, a remarkable inflammatory reaction could be seen in the LAD-augmented autografts early postoperation. Compared with the nonaugmented autografts, tissue formation and remodeling were delayed in the augmented group. After 1 and 2 years, the morphology of the autograft tissue was similar in both the augmented and nonaugmented group and differed from that of a normal PCL. The LAD was surrounded by a chronic inflammatory reaction, and collagen fiber ingrowth into the LAD was not observed. Using transmission electron microscopy, small diameter collagen fibrils were predominant in the graft tissue of both groups. Thus, a better remodeling of the autograft tissue in the presence of the LAD could not be demonstrated in this particular study. The value of synthetic augmentation of biological grafts in PCL reconstruction seems to be questionable at present.Supported by the Deutsche Forschungsgemeinschaft     

Extensor Mechanism Disruption After Contralateral Middle Third Patellar Tendon Harvest for Anterior Cruciate Ligament Revision Reconstruction

The contralateral central third patellar tendon autograft is a reliable graft choice for revision, and recently, for primary reconstruction of the anterior cruciate ligament (ACL). We report 2 complications including a lateral third tibial tuberosity fracture and a distal patellar tendon avulsion with contralateral patellar tendon autograft with disruption of the extensor mechanism of the donor knee. A patient sustained a lateral tibial tuberosity fracture of the donor knee and underwent open reduction and internal fixation. At 1-year follow-up, she had no extensor lag and full range of motion. Another patient sustained a distal patellar tendon avulsion of the donor knee and underwent primary repair. Three years postoperatively, she had a full range of motion and no extensor lag. Although contralateral middle third patellar tendon autograft for primary and revision ACL reconstruction is established in the literature, extensor mechanism complications can occur. Technical considerations are important to avoid weakening the remaining patellar tendon insertion. Postoperative nerve blocks or local anesthetics may alter pain feedback for regulation of weight bearing and contribute to overload of the donor knee.     

Effect of Donor Age on Patellar Tendon Allograft ACL Reconstruction

Anterior cruciate ligament reconstruction with patellar tendon allograft tissue is a common orthopedic procedure. It is unknown what effect, if any, the donor age has on clinical outcomes. Biomechanical studies have shown the strength of cadaveric patellar tendon to be independent of age, but no clinical studies have evaluated patient outcomes related to this variable. The purpose of this study was to evaluate the effect of allograft donor age on clinical outcomes of patients undergoing allograft anterior cruciate ligament reconstruction with patellar tendon allograft.Case logs were reviewed to identify primary anterior cruciate ligament reconstruction with allograft patellar tendon by a single surgeon using a standard endoscopic transtibial technique with interference screw fixation. Revision and multiligamentous surgeries were excluded. Seventy-seven patients who met these criteria were identified. Allografts were fresh-frozen, aseptically harvested patellar tendons from a single tissue bank. The donor age was obtained. Clinical outcomes were obtained by contacting patients by telephone and retrospective chart review. Pre- and postoperative Lysholm and Tegner knee scores were used for comparison.Data from 75 patients with an average follow-up of 24 months were obtained. Average donor age was 44 years (range, 14-65 years), and average patient age was 37 years (range, 18-60 years). Statistical analysis of pre- and postoperative Lysholm scores demonstrated statistically significant improvement (P?.001). Using donor age as a continuous variable, no effect was found on postoperative improvement in Lysholm score or Tegner score (P=.6).     

The comparison of functional results of anterior cruciate ligament injuries treated with semitendinosus tendon and central one-third of patellar tendon autografts

The results of ACL reconstructions with autologus grafts taken from semitendinosus tendon and patellar ligament are presented. There were 78 patients in four groups. Patient age ranged from 15 to 47 years. The period of observation varied from 1 to 10 years, average 3.5. The first group consisted of 28 people treated with single semitendinosus tendon graft. In the second group there were 12 patients with acute ACL injuries treated by reinsertion of torn ligament attachment augmented by semitendinosus tendon. The third group of 18 persons had an ACL reconstruction with central one-third of patellar ligament fastened with thread loops on bone screws or staples. The last group of 20 patients had ACL reconstruction with central one-third of patellar ligament autograft. All patients were prospectively evaluated according to the Hospital for Special Surgery and the Lysholm and Gillquist scales. The statistical analysis clearly reveals the best results in the fourth group of patients, who had graft fixation with interference screws. Received: 4 April 2001/Accepted: 23 April 2001     

Revision anterior cruciate ligament reconstruction using the lateral third of the ipsilateral patellar tendon after failure of a central-third graft: a preliminary report on 10 patients

Long-term outcomes were reported for 10 (77%) of 13 cases of revision anterior cruciate ligament (ACL) reconstruction using the lateral third of the ipsilateral patellar tendon as a graft. All primary ACL reconstructions were ipsilateral central-third bone-patellar tendon-bone graft procedures. Mean age at follow-up was 30.7 years, and mean time from revision ACL surgery to follow-up was 42.9 months. At follow-up, average KT-1000 difference between knees was 2.4 mm. All patients had a negative pivot shift, extension within 5 degrees of the contralateral knee, and flexion within 15 degrees. Mean bilateral comparison ratios for isokinetic strength and hop testing were: extension, 83.5%; flexion, 96%; and single-leg hop 96.9%. No patella fractures or tendon ruptures had occurred. All patients had returned to their previous work level, and 8 of the 10 patients could participate in at least "moderate" sports activities (e.g., skiing and tennis). The results were comparable to published outcome reports for both primary and revision ACL reconstruction. The lateral third of the ipsilateral patellar tendon is a good graft option for revision ACL reconstruction.     

Initial biomechanical properties of anterior cruciate ligament reconstruction autografts

To provide more information to consider when selecting a reconstruction technique, we did a side-by-side comparison of some of the initial biomechanical properties of currently accepted reconstruction methods. Our research hypotheses were that a quadrupled, woven semitendinosus and gracilis graft is as strong as any of the other commonly used graft materials and that quadrupling and weaving the hamstring graft may increase the stiffness of the overall construct Using lower extremity cadaveric specimens harvested from young donors, we fashioned seven each of seven types of graft: 9-mm, 10-mm, and 11-mm-wide patellar tendon graft (PTG); 10-mm-wide central quadriceps tendon graft; doubled semitendinosus graft; tripled semitendinosus graft; and quadrupled, woven semitendinosus and gracilis graft. Specimens were stripped of remaining soft tissue, and anterior cruciate ligament (ACL) constructs were created for biomechanical testing. The tibia was translated anteriorly on the femur, mimicking a pivot shift maneuver, andfailure strength, failure mechanism, and construct stiffness were recorded. No differences in mean strength were detected. The quadrupled, woven graft was significantly stiffer than the doubled semitendinosus graft and no less stiff than any of the PTG constructs. All grafts showed similar and adequate initial absolute strength to reconstruct the ACL. Quadrupling and weaving the semitendinosus and gracilis graft increases the stiffness of the reconstructed specimen to a level statistically similar to that of specimens reconstructed with a PTG.     

Anterior Cruciate Ligament Reconstruction

The bone-patellar tendon-bone has been widely used and considered a good graft source. The quadriceps tendon was introduced as a substitute graft source for bone-patellar tendon-bone. We compared the clinical outcomes of anterior cruciate ligament reconstructions using central quadriceps tendon-patellar bone and bone-patellar tendon-bone autografts. We selected 72 patients who underwent unilateral anterior cruciate ligament reconstruction using bone-patellar tendon-bone between 1994 and 2001 and matched for age and gender with 72 patients who underwent anterior cruciate ligament reconstruction using quadriceps tendon-patellar bone. All patients were followed up for more than 2 years. We assessed anterior laxity, knee function using the Lysholm and International Knee Documentation Committee scores, and quadriceps strength, the means of which were similar in the two groups. More patients (28 or 39%) in the bone-patellar tendon-bone group reported anterior knee pain than in the quadriceps tendon-patellar bone group (six patients or 8.3%). Anterior cruciate ligament reconstruction using the central quadriceps tendon-patellar bone graft showed clinical outcomes comparable to those of anterior cruciate ligament reconstruction using the patellar tendon graft, with anterior knee pain being less frequent in the former. Our data suggest the quadriceps tendon can be a good alternative graft choice. LEVEL OF EVIDENCE: Level III Therapeutic study.     

Two-stage reconstruction with autografts for knee dislocations

Traumatic knee dislocations are severe injuries that involve damage to the anterior cruciate ligament, the posterior cruciate ligament, and the lateral or medial ligamentous structures. There are no established methods of treatment. The objective of the current study was to report the clinical outcome of a two-stage autologous reconstruction on nine knees (eight patients). The mean followup was 40.1 months. The first stage of the reconstruction was done at a mean of 2 weeks after the injury, and the posterior cruciate ligament was reconstructed by an arthroscopically assisted technique using contralateral autogenous hamstring tendon as the graft material. Three months later, the second stage of the reconstruction was done for the ligaments that had not healed with conservative treatment. Arthroscopically assisted anterior cruciate ligament reconstruction was done on all of the knees using the ipsilateral autogenous hamstring tendon or bone-patellar tendon-bone as the graft material. At the same time, a medial collateral ligament reconstruction using an autogenous semitendinosus tendon was done on one knee, and reconstruction of the posterolateral ligamentous structures using a biceps tendon was done on three knees. Each of the knees that was reconstructed was capable of full extension, and the mean degree of passive flexion was 139.5 degrees +/- 5.2 degrees. The mean side-to-side difference in anteroposterior total laxity (KT-1000 arthrometer, manual maximum) was 2.3 +/- 1.9 mm. None of the knees had lateral or medial instability. All of the injured ligaments were able to be reconstructed with autografts, and severe contracture was able to be prevented. A good clinical outcome can be achieved when two-stage reconstruction is used for traumatic knee dislocations.     

Mechanoreceptors of patellar tendon used for ACL reconstruction: Rabbit experiments

In 17 Japanese white rabbits (weighing 2.6-3.7kg), the anterior cruciate ligament of the right knee was resected and then reconstructed, using the lateral half of the patellar tendon. The contralateral side served as control. Rabbits were killed 10, 20, or 30 weeks postoperatively. Then the reconstructed ligament was harvested and stained, using a modified gold chloride method. Under the light microscope, sensory nerve endings in serial sections were counted after being morphologically identified.

With respect to the number of Pacinian and Ruffini corpuscles, there were no significant differences between the reconstructed ligament and the control patellar tendon at any time after surgery.     

Patellar tendon augmentation after removal of its central third limits joints tissue changes.

The central third of the patellar tendon is commonly used to reconstruct the injured anterior cruciate ligament. Some studies have noted changes in joint tissues following this procedure. It has been postulated that these changes may be associated with increased stress on the remaining tendon following harvest of the graft. In our study, the central third of the patellar tendon was excised in three groups of rabbits. The central tendon defects in two of the three groups were fitted with different augmentation devices to augment the host tendon during the healing process. All rabbits followed a daily treadmill exercise regimen for 12 weeks following the operation. Biomechanical testing of the tendon revealed that in nonaugmented tendons the cross-sectional area and the length of the patellar tendon significantly increased 112 and 16%, respectively. There was histological evidence of host-tendon remodeling throughout the cross section and extensive fibrosis in the infrapatellar fat pad. Augmentation of the tendon significantly reduced these changes, with the least change noted in the group with the greatest augmentation. The rabbits with augmentation devices retained tendon dimensions similar to those of the contralateral intact tendon, and tendon remodeling occurred only in the defect area. The rabbits with augmentation devices exhibited little to no fibrosis of the fat pad. Structural properties of augmented and nonaugmented tendons were similar despite the size differences, indicating higher tissue quality in the augmented tendons. This study suggested that complications of the knee joint (i.e., tendon proliferation and fat pad fibrosis) noted after anterior cruciate-ligament reconstruction with the autogenous patellar tendon may be limited by the implantation of an augmentation device.     

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.     

内侧髌股韧带重建术治疗复发性髌骨脱位的疗效研究

目的探讨游离肌腱移植重建内侧髌股韧带的手术方法及治疗复发性髌骨脱位的疗效。方法自2006年6月至2012年7月收治复发性髌骨脱位患者共40例（47膝）,男10例（12膝）,女30例（35膝）,年龄7～51岁,平均19．4岁。全部经膝关节镜检最后确诊,其中43膝采用游离自体半腱肌,4膝采用异体肌腱,通过髌骨双隧道移植重建内侧髌股韧带,镜下动态调整移植肌腱的张力,使髌股关节对合达到正常,并用挤压螺钉将肌腱游离端固定在股骨止点。其中8例（10膝）同时行髌韧带止点内移术。结果有36例（42膝）患者获得随访,随访时间3—70个月,平均随访23个月。临床疗效评价包括髌骨主观稳定性评估、Lysholm膝关节评分及Insall疗效标准（1976年）。术后髌骨外推试验和恐惧试验均为阴性。手术前后Lysholm评分术前平均为（63．1±9．1）分,术后评分为（87．1±6．4）分,手术前后的差异有统计学意义（t=21．7,P〈0．05）。按Insall疗效标准,优良率为85．7％。结论采用以游离肌腱重建MPFL为主的综合术式治疗复发性髌骨脱位,手术效果满意。     

Simultaneous Reconstruction of Ruptured Anterior Cruciate Ligament and Medial Patellofemoral Ligament With Ipsilateral Quadriceps Grafts

Rupture of the anterior cruciate ligament is a well-known entity and causes anteroposterior and rotational instability of an injured knee. Rupture of the medial patellofemoral ligament is less frequent, and its insufficiency causes patellar instability. Several techniques have been described for the reconstruction of each ligament. The 2 lesions and following instabilities can coexist, and both ligaments can be reconstructed simultaneously. We report on 2 cases, 1 recreational sportswoman and 1 high-level sportswoman, with coexisting lesions treated surgically by a single-step procedure using ipsilateral graft of the quadriceps tendon for reconstruction of medial patellofemoral ligament and anterior cruciate ligament. The advantage of this procedure is that there is only 1 donor site, and thus lower donor-site morbidity, while the strength of either neoligament is not sacrificed. The technique is described here.     

Use of patellar allograft to reconstruct a patellar tendon-deficient knee after total joint arthroplasty

A catastrophic complication after total knee arthroplasty (TKA) is rupture of the patellar tendon. Several techniques for treatment have been described, including cast immobilization with or without operative repair, the use of a semitendinosus, fascia lata, or hamstring tendon autogenous graft, the use of a Dacron 4-mm vascular graft (U.S. Catheter and Instrument, Glen Falls, NY), the use of bovine xenograft and even transplantation of an entire allograft extensor mechanism. Treatment results of patellar tendon rupture after TKA can be discouraging. Altered tissue quality secondary to connective tissue diseases, diabetes, rheumatoid arthritis, lupus erythematosus, secondary hyperparathyroidism, or concurrent steroid medications contributes to poor results. Additionally, no one treatment has provided consistent clinical success. Successful treatment of a patient with a ruptured patellar tendon after TKA using the bone-patellar tendon-bone allograft commonly used for anterior cruciate ligament reconstruction is reported.     

Anterolateral rotatory instability of the knee. Cadaver study of extraarticular patellar-tendon transposition

A cadaver knee-testing system was used to analyze the effect of an extraarticular reconstruction for anterolateral rotatory instability in which the lateral one third of the patellar tendon with a patellar bone block was transposed to the lateral femoral condyle. Ligament and reconstruction tendon forces were measured using buckle transducers, and joint motion was measured using an instrumented spatial linkage as 90 N anteriorly directed tibial loads were applied to seven knee specimens at 0 degree, 30 degrees, 60 degrees, and 90 degrees of flexion by a pneumatic load apparatus. This was done for each knee with first an intact, then an excised anterior cruciate ligament, and finally the extraarticular reconstruction. Forces in the transposed graft exhibited an isotonic pattern over the flexion range, unlike the intact anterior cruciate ligament, which was more highly loaded in extension than in flexion. The transposition of the patellar tendon led to external rotation of the tibia in both unloaded and anterior load conditions throughout flexion. Collateral ligament forces increased with anterior cruciate ligament excision, with the force in the medial ligament remaining higher than normal with the reconstruction, while the lateral forces became lower than normal.     

关节镜下股四头肌腱-髌骨块重建后交叉韧带

目的探讨关节镜下利用股四头肌腱-髌骨块嵌入和可吸收螺钉挤压固定方法重建后交叉韧带(posterior curciate ligament,PCL)的效果。方法33例PCL损伤患者,术前膝关节功能Ly-sholm评分平均51.3(32～78)分,IKDC分级:C级27例,D级6例。先获取股四头肌腱移植物并进行修整和预牵引,再制作胫骨及股骨隧道,然后植入股四头肌腱,将与之连接的髌骨块用可吸收螺钉挤压固定。结果所有患者均获得随访,平均18(3～37)个月,无血管神经损伤及移植物失败等严重并发症。所有患者均无膝关节不稳定症状,除5例患者剧烈活动或长时间活动后关节疼痛、2例患者轻微活动时关节疼痛外,其余患者关节疼痛症状明显缓解。术后Lysholm评分平均87.7(76～100)分,显著高于术前(P<0.01);IKDC分级A级23例,B级10例,明显优于术前(P<0.01)。结论采用股四头肌腱移植物对取材部位无不良影响,移植物生物力学特性更接近PCL,且可以切取任意长度和宽度,保证远大于PCL的强度。移植物固定采用本文设计的骨块嵌入和可吸收螺钉挤压的方法,成功率高、并发症少,有明显优越性。     

Shortening of the patellar tendon length does not influence the patellofemoral alignment in a cadaveric model

Introduction Anterior cruciate ligament (ACL) reconstruction with the use of autograft tissue represents the standard treatment. The use of a bone-patellar tendon-bone transplant for symptomatic ACL deficiency achieves good long-term results. The purpose of the study was to investigate in a cadaveric model whether reproducible patellar tendon shortening changes the patellofemoral alignment.Materials and methods Using five cadaveric knees, an MRI investigation was performed with the patellar tendon left unchanged, shortened 5 mm and shortened 10 mm, respectively, in both 20 and 45° of knee flexion. The lateral patellofemoral and the congruence angles were measured and compared using a one-way analysis of variance for repeated measurements.Results Shortening the patella tendon by approximately 20% did not significantly influence the patellofemoral alignment.Conclusion Although anterior cruciate ligament-reconstruction using the patellar tendon has become a standard procedure, postoperative problems such as anterior knee pain, and patellofemoral osteoarthritis occur quite often. In this cadaver study we did not find a significant difference for the patellofemoral alignment, irrespective of the patellar tendon length.