Amputation of the knee joint in vascular diseases

Reported are 97 extensive amputations in 87 patients from 1975 to 1977. Postoperative early mortality was 47% and depended on the disease and the various factors that made amputation necessary. Amputations in chronic occlusive vascular disease without septicemia had a far lower mortality, 10%. Amputations in patients with septicemia resulted in a mortality of 90%. According to Burgess, amputations of the lower leg, exarticulation in the knee joint, and myeloplastic and open amputation of the thigh should be considered in that order. Exarticulation in the knee joint is only feasible in the presence of an open, deep, femoral artery.     

Migration of hip revision stems into the knee joint: alternative treatment modalities: technical note

We report two unusual cases of stem penetration of long shaft femoral prosthesis into the knee joint after revision total hip arthroplasty. In both patients, the protruded tip of the stem interfered with the tibial plateau and averted the knee joint from full range of motion. To avoid further extensive surgery, the tips of the femoral stem were excised using a high speed-cutter. Both patients had immediate improvement in range of motion postoperatively, fast and uncomplicated rehabilitation, immediate pain relief, and good radiological results. If this rare complication occurs, we recommend for a primary intervention to cut the tip of the stem because replacement of the prosthesis would be a long lasting and very exhaustive surgery for affected patients.     

Is the implantation of hinged knee joint prostheses still justifiable today? 15 years' experience using the Blauth knee joint prosthesis

In objection to knee hinge prostheses there is often mentioned a higher complication rate. An increased load impact on the bone-cement interface results from the close connection of tibial and femoral components. This is assumed to cause bad results, as reported from early artificial knee joint replacements, characterised by weight bearing axes and direct contact metal to metal. These are contrasted to long term results of the Blauth hinge prosthesis. The Blauth prosthesis is constructed according to the low friction principle without a weightbearing axis. A prospective multicentric long term follow-up study reports on 556 prostheses. 463 (83%) were controlled between 1 and 15 years after operation (average: 43 months). Aseptic loosenings had to be confirmed in 1.3% of the patients, deep infections in 2.6%. The survival analysis did not show an erratic deterioration in dependence of the observation period. After 10 years there is still a probability of 89% that a prosthesis does not show a deep infection or loosening. The efficiency of artificial knee joint replacement by hinge joints should therefore not be judged on the results of the first generation of these models.     

膝关节单髁置换术下肢力线纠正及假体位置角度研究进展

下肢力线与单髁假体位置角度是影响单髁置换术假体长期生存率及临床疗效的重要因素。下肢力线矫正不足将加速假体磨损进而减少假体生存率,下肢力线矫正过度会加速对侧间室关节炎的进展。通常认为单髁置换术下肢力线应纠正轻度内翻,然而部分学者的研究认为术后下肢力线对单髁置换术后功能评分和假体生存率无影响。股骨、胫骨假体位置不佳将造成患者膝关节不明原因疼痛甚至假体磨损,但股骨胫骨假体最佳位置存在争议。通常认为单髁置换术胫骨平台后倾角应纠正在3°~7°,但部分学者认为胫骨平台后倾角的改变过大也将影响膝关节间隙平衡及膝关节活动度。本文研究认为单髁置换术下肢力线的纠正至轻度内翻仍是单髁置换术最佳下肢力线,股骨与胫骨假体最佳位置有待进一步生物力学研究证实,胫骨平台后倾角的纠正应该根据术前患者具体原始解剖角度而变化。     

Knieexartikulation und transgenikul?re Amputation

Objective

A knee disarticulation or a through-knee stump is superior compared to a transfemoral stump. The thigh muscles are all preserved, and the muscle balance remains undisturbed. The range of motion of the hip joint is not limited. The bulbous shape of the stump allows full weight bearing at the stump end and can easily be fitted with a prosthesis. An amputee with a bilateral knee disarticulation is able to walk ??barefoot??.

Indications

A more distal amputation level, e.g., an ultra-short transtibial amputation, is not possible. Important alternative to transfemoral amputations. Possible for any etiology except for Buerger-Winiwarter??s disease. New indications are infected and loosened total knee replacements.

Contraindications

Preservation of the knee joint is possible.

Surgical technique

Knee disarticulation is a very atraumatic procedure, compared to transfemoral amputations. Neither bones nor muscles have to be severed, just skin, ligaments, vessels, and nerves. Even the meniscal cartilages may be left in place to act as axial shock absorbers. The cartilage of the femur is not resected, but only bevelled in case of osteoarthritis. There are no tendon attachments or myoplastic procedures necessary. The patella remains in place and is held in position only by the retinacula. Skin closure must be performed without the slightest tension, and if possible not in the weight-bearing area. Transcondylar amputations across the femoral condyles only are indicated when there are not sufficient soft tissues for wound closure of a knee disarticulation. Alternatives as the techniques of Gritti, Klaes, and Eigler, the shortening of the femur and the Sauerbruch??s rotation plasty [14] are presented and discussed.

Postoperative management

The risk of decubital ulcers is rather high. Correct bandaging of the stump is, therefore, particularly important. Prosthetic fitting is possible 3?C6?weeks after surgery. The type of prosthesis depends on the amputee??s activity level.

Results

The superior performance of amputees with knee disarticulations in sports prove the superiority of that amputation level compared to transfemoral amputees. However, because less than 5% of amputations are knee disarticulations, statements about statistical significance cannot be made. On the other hand, one should do everything to preserve an ultra-short transtibial stump.     

Knee disarticulation versus above-knee amputation.

If below-knee amputation is impossible, knee disarticulation should be considered before above-knee amputation, regardless of age and etiology. Knee disarticulation which leaves the femur and patella untoched offers many advantages. The surgical technique is simple and non-traumatic since no bone or muscle tissue is to be dissected. The thigh muscles are completely preserved and thus there is no muscular imbalance. The stump permits total end bearing and its bulbous shape permits easy and firm attachment of the prosthesis. A specially designed double-wall socket and various types of knee joints are presented. Modern prostheses are superior to above-knee prostheses with regard to function, comfort and cosmesis. Results of 72 patients of all age groups are presented and discussed.     

Therapy in unilateral sirenomelia: report of one case

A 17-month-old male infant was referred to us with a unilateral sirenoid malformation in 1970. Besides urogenital and lumbosacral vertebral defects, the right knee was flexed 160 degrees, and the hip externally rotated and abducted. The thigh and calf were connected by a soft tissue bridge with the heel fixed to the ischial region. Arteriography showed that the foot and lower leg were supplied by the profunda femoris artery through the soft tissue bridge. The lower leg had only a very small supply from the popliteal artery. Therefore, an amputation by disarticulation at the knee joint was performed. A few months later, in addition, the hip flexion contracture was released. The boy was taught to walk with a prosthesis. At the age of 31 years, he has a sedentary job and is more troubled by his urogenital than his orthopaedic defects. He prefers to walk with crutches and for a few years has no longer used his prosthesis.     

In vitro investigation of knee joint kinematics following cruciate retaining versus cruciate sacrificing total knee arthroplasty

The aim of this biomechanical study was to investigate knee joint kinematics following total knee arthroplasty. We compared eight congruent posterior cruciate ligament retaining and four ultracongruent cruciate sacrificing Natural Knee prostheses to the untreated human cadaveric knee joint. A six-degree-of-freedom testing device was used to evaluate knee joint kinematics with a load of 300 Newton and without load application (0 Newton). Statistical analysis was performed using the Wilcoxon rank sum test. A significant increase in antero-posterior translation and tibial rotation was seen in both types of total knee arthroplasty. Implantation of the ultracongruent prosthesis was followed by distinctly more kinematic changes in comparison to the congruent prosthesis. Load application of 300 Newton leads to an anterior dislocation of the femoral component of the ultracongruent prosthesis at 60 degrees of flexion in vitro, indicating an increased demand of compensatory muscular activity in vivo.     

Revision of the Gunston polycentric knee arthroplasty with total knee arthroplasty

The Gunston polycentric knee arthroplasty, first designed and performed by Frank Gunston in 1971, is the first prosthesis considering the natural knee biomechanics. Although the polycentric knee arthroplasty showed encouraging results to relieve pain and to preserve the preoperative range of motion and joint instability, the improvements in prosthesis design and arthroplasty technology rapidly made the polycentric knee prosthesis obsolete. Herein, we report a 58-year old male patient who had revision of the Gunston polycentric knee arthroplasty with total knee arthroplasty performed 32 years after the initial operation.     

Salvage of knee joint tumor prosthesis using turnover reverse-flow descending branch of lateral circumflex femoral artery as recipient vessel for the free ALT flap: a case report

To report an unusual case using free anterolateral thigh (ALT) fasciocutaneous flap to salvage a knee joint tumor prosthesis. The turnover reverse-flow descending branch of the ipsilateral lateral circumflex femoral artery (LCFA) was successfully used as a recipient vessel for the contralateral free ALT flap. A 30-year-old male patient with high-grade and fibroblastic-type osteogenic sarcoma at the right proximal tibia received a tumor resection and tumor prosthesis to salvage the right knee joint. No local antegrade recipient vessels were available near the defect at the right knee. No sizable perforator could be found when trying to harvest the reverse ipsilateral ALT flap. The turnover reverse-flow descending branch of the ipsilateral LCFA and its concomitant veins were used as recipient vessels to supply the contralateral free ALT flap. The flap survived well without obvious venous congestion or sequela. The turnover reverse-flow descending branch of the LCFA and its concomitant veins can be successfully used as recipient vessels to supply a free ALT flap.     

Knee disarticulation with intercondylar patellofemoral arthrodesis. An improved technique

As compared to an above-knee amputation, the knee disarticulation has several marked advantages that are well known and accepted by most surgeons. However, it has not gained popularity because it leaves a double condylar, bulbous, uneven stump, which is difficult to fit into the base of the socket. In ten patients, a modified surgical technique included moderate trimming of the femoral condylar prominences and patellofemoral arthrodesis in the intercondylar notch. This produces a conical stump with a large area for end bearing, and at the same time allows the standard suction-socket fitting without ischial weight bearing. The average age was 33.1 years (range, ten to 75 years). The indication for amputation was trauma in four cases, tumor in three cases, chronic osteomyelitis in one, ischemia of the leg in one, and congenital malformation in one. Average length of follow-up study was four years (range, one to 9.8 years). Complications were stump ulceration in one case and fistula formation in two cases. Nine patients achieved full weight-bearing ambulation with an end-bearing type of prosthesis. The remaining patient was not fitted with a prosthesis prior to his death from a systemic medical illness. Union of the patellofemoral arthrodesis was achieved in all ten cases. This procedure is recommended whenever knee disarticulation is indicated and ambulation expected. Significant improvement over standard knee disarticulation or distal above-knee amputation can be achieved.     

全膝关节置换术中股骨假体屈曲对髌股关节生物力学影响的实验研究

[目的]探讨全膝置换术中股骨假体矢状位上屈曲对髌股关节生物力学的影响,为临床指导人工膝关节置换的手术技术提供实验依据,以减少术后髌股关节的并发症。[方法]取正常国人新鲜冷冻尸体的5个膝关节作为研究对象,模拟膝关节自站立位屈膝下蹲的动作,设计制作膝关节实验架,与生物力学测试仪共同搭建实验平台。人工膝关节采用DePuy PFC假体全膝系统,手术由同一位有经验的术者实施以控制实验误差,置换髌骨。比较股骨假体相对于按下肢力线位、前屈5°、10°及后屈5°、10°、15°位置时的髌股关节的生物力学指标。选择屈膝30°、60°、90°、120°为观察角度,采用美国Tecscan公司生产的感测片测定髌股关节接触压峰值,最后软件处理得到数字化的结果。[结果]除了在膝关节屈曲30°、60°、90°,股骨假体前屈5°时,髌股关节内侧间隙接触压峰值与下肢力线位相比较无显著性差异(P>0.05),其余各种屈膝角度下,股骨假体不同屈曲角度所致髌股关节内外侧间隙接触压峰值与下肢力线位比较有显著性差异(P<0.05)。股骨假体后屈角度越大,峰值的升高越明显。[结论]全膝关节置换术中,股骨假体在矢状位上争取按下肢力线位置入,以降低术后并发症的发生。     

Extra-articular fractures near the knee and concomitant knee damage]

While the prognosis of intra-articular fractures of the knee joint is determined by the reconstruction of the articular surfaces, ligamentous damage and resulting joint instability is a main problem with extra-articular fractures neighbouring the knee. In a follow-up of 43 cases of A 1-3 fractures according to the AO/ASIF classification, 37.2% of the patients revealed concomitant ligamentous damage. Especially supracondylar femoral fractures and the avulsion fractures of the posterior cruciate and lateral collateral ligament are at higher risk.--Ligamentous ruptures accompanying avulsion fractures should be treated primarily according to the rules of knee joint surgery. In cases of supracondylar femoral fractures after open reduction and internal fixation the recovery of knee joint motion is more important than joint stability. Therefore ligamentous repair has to be performed secondarily if necessary.     

The influence of joint line position on knee stability after condylar knee arthroplasty

Using a special knee-testing device, ten knees obtained at autopsy were subjected to varus-valgus, anterior-posterior, and flexion-rotation analysis in the intact state and after total knee arthroplasty. The ten knees showed no significant change in stability after knee replacement when the joint line was maintained in its natural position. When the femoral component was repositioned 5 mm proximally and 5 mm anteriorly, a significant increase in laxity occurred during midflexion. When the joint line was shifted 5 mm distal and 5 mm posterior to its anatomic location, significant tightening occurred in midrange of motion. Coupled rotation of the tibia with knee flexion was decreased after surgery in all knees with no specific relationship to joint line position. Coupled rotation with varus-valgus testing, however, remained within the normal range through the first 30 degrees of flexion only when the joint line was restored to its normal anatomic position. Stability in condylar knee arthroplasty is in part dependent on position of the joint line. Surgical techniques that rely on restoring the flexion and extension gap without regard to joint line position may result in alteration of varus-valgus or anterior-posterior displacement in midrange flexion.     

Three dimensional kinematics of the knee joint

The study deals with 3 d-Kinematics and stability patterns according to a knee joint testing machine. During flexion the lateral femoral condyle displays near extension pure rolling, near flexion pure gliding, on the medial side this ratio is vice versa. 41 knee joint specimen provided internal-external transverse rotation during there whole range of motion. Additional varus rotation and medial translation occurred. In osteoarthritis the movement patterns were completely changed.     

Penetration of a long stem prosthesis into the knee joint: a complication of total hip replacement

The unusual occurrence of penetration of the stem of a femoral prosthesis into the knee joint during total hip replacement and the method used to deal with this complecation successfully, without replacing the prosthesis, is described.     

North American experience with knee disarticulation with use of a posterior myofasciocutaneous flap. Healing rate and functional results in seventy-seven patients

BACKGROUND: A method for closure of a knee disarticulation wound with use of the posterior calf skin and gastrocnemius muscle bellies as an integral flap, without destruction of the perforating vessels, was described by Klaes and Eigler in 1985. The purposes of the present study were to report our experience with use of this technique in a prospective series of knee disarticulations and to determine the healing rate and the functional result after use of the flap. METHODS: Eighty knee disarticulations, performed with use of the flap described by Klaes and Eigler, in seventy-seven patients were evaluated in a prospective manner. The patients ranged in age from nineteen to ninety-two years (mean, sixty-four years). Thirty-one patients had diabetes mellitus with peripheral vascular disease, and twenty-nine had peripheral vascular disease alone as the primary cause of gangrene. Fourteen patients had a traumatic injury, two had a sarcoma, and one had Ollier disease. RESULTS: Five patients died in the early postoperative period, leaving seventy-five stumps available for evaluation. A total of sixty-seven stumps (89 percent) healed; sixty-three (84 percent) of them healed primarily. Major wound dehiscence occurred in seven stumps (9 percent), requiring revision to the transfemoral level. Six of those patients had a serum albumin level of less than thirty millimoles per liter. Twenty-two (81 percent) of the twenty-seven patients who could walk before surgery were able to walk with a prosthesis after it. CONCLUSIONS: This simple technique offers reliable healing of knee disarticulation wounds in properly selected patients with a variety of conditions. It also provides comfortable end-bearing for prosthesis wearers because the distal flap is thick and mobile.     

Computational analysis of customized cruciate retaining total knee arthroplasty restoration of native knee joint biomechanics

The purpose of this study was to verify if customized prosthesis better preserves the native knee joint kinematics and provides lower contact stress on the polyethylene (PE) insert owing to the wider bone preservation than that of standard off‐the‐shelf prosthesis in posterior cruciate‐retaining type total knee arthroplasty (TKA). Validated finite element (FE) models for were developed to evaluate the knee joint kinematics and contact stress on the PE insert after TKA with customized and standard off‐the‐shelf (OTS) prostheses as well as in normal healthy knee through FE analysis under dynamic loading conditions. The contact stresses on the customized prosthesis decreased by 18% and 8% under gait cycle loading conditions, and 24% and 9% under deep‐knee‐bend loading conditions, in the medial and lateral sides of the PE insert, respectively, compared with the standard OTS prosthesis. The anterior‐posterior translation and internal‐external (IE) rotation in customized TKA were more similar to native knee joint behaviors compared with standard OTS TKA under gait loading conditions. The difference from normal knee kinematics was lower for femoral rollback and IE rotation in customized TKA than in standard OTS TKA in the deep‐knee‐bend condition. In general, customized prostheses achieve kinematics that are close to those of the native healthy knee joint and have better contact stresses than standard OTS prostheses in gait and deep‐knee‐bend loading conditions.     

The effects of severe femoral bone loss on the flexion extension joint space in revision total knee arthroplasty: a cadaveric analysis and clinical consequences

Five revision total knee arthroplasties (TKAs) involving severe femoral bone loss were performed in 1994. Each had sufficiently severe femoral bone loss in which collateral ligament origins and posterior capsular attachments were violated. A paradoxical phenomenon was observed in each case. Unlike primary TKAs, in which larger distal femoral bone resection leads to laxity of the knee joint in extension, these cases with severe distal femoral bone loss, after initial component selection, developed the opposite situation, a flexion contracture. It was hypothesized that femoral bone loss involving collateral ligament origins would permit distraction of the tibia below the femur with the knee held in flexion, but when the knee was brought to full extension, intact posterior structures would maintain a normal tibial position. To investigate this hypothesis, six fresh-frozen cadaveric lower limbs were tested in full extension and 45 degrees and 90 degrees of flexion after release of the femoral attachments of the collateral ligaments and the posterior capsule from the femur. Joint space changes were measured via a motion tracking device. Results showed that with loss of collateral attachments, 17.2+/-8.9 mm of joint space is created in 90 degrees of flexion, whereas the joint space in full extension is conserved (1.5+/-1.7 mm). With additional loss of the posterior capsule, the joint space at 90 degrees of flexion increased to 26.2+/-6.1 mm, with minimal changes in the extension gap (3.4+/-0.8 mm). Distal femoral bone loss was associated with an increase in the flexion gap compared to the extension gap.     

Differences in the stress distribution in the distal femur between patellofemoral joint replacement and total knee replacement: a finite element study

ABSTRACT: BACKGROUND: Patellofemoral joint replacement is a successful treatment option for isolated patellofemoral osteoarthritis. However, results of later conversion to total knee replacement may be compromised by periprosthetic bone loss. Previous clinical studies have demonstrated a decrease in distal femoral bone mineral density after patellofemoral joint replacement. It is unclear whether this is due to periprosthetic stress shielding. The main objective of the current study was to evaluate the stress shielding effect of prosthetic replacement with 2 different patellofemoral prosthetic designs and with a total knee prosthesis. METHODS: We developed a finite element model of an intact patellofemoral joint, and finite element models of patellofemoral joint replacement with a Journey PFJ prosthesis, a Richards II prosthesis, and a Genesis II total knee prosthesis. For each of these 4 finite element models, the average Von Mises stress in 2 clinically relevant regions of interest were evaluated during a simulated squatting movement until 120 degrees of flexion. RESULTS: During deep knee flexion, in the anterior region of interest, the average Von Mises stress with the Journey PFJ design was comparable to the physiological knee, while reduced by almost 25% for both the Richards II design and the Genesis II total knee joint replacement design. The average Von Mises stress in the supracondylar region of interest was similar for both patellofemoral prosthetic designs and the physiological model, with slightly lower stress for the Genesis II design. CONCLUSIONS: Patellofemoral joint replacement results in periprosthetic stress-shielding, although to a smaller degree than in total knee replacement. Specific patellofemoral prosthetic design properties may result in differences in femoral stress shielding.