Natural history of fixed flexion deformity following total knee replacement: a prospective five-year study

We investigated fixed flexion deformity (FFD) after total knee replacement (TKR). Data relating to 369 cruciate-retaining unilateral TKRs performed at a single institution were collected prospectively. Fixed flexion was measured pre-operatively and at one week, six months, 18 months, three years and five years after surgery.Using binary logistic regression, pre-operative FFD was a predictor of post-operative FFD > 10 degrees at one week (p = 0.006) and six months (p = 0.003) following surgery. Gender was a predictor at one week (p = 0.0073) with 24% of women showing a FFD > 10 degrees compared with 37% of men.We have shown that a gradual improvement in knee extension can be expected up to three years after surgery in knees with FFD. By this time residual FFD is mild or absent in the majority of patients, including those who had a severe pre-operative FFD.     

Patients with fixed flexion deformity after total knee arthroplasty do just as well as those without: ten-year prospective data

Range of motion (ROM) is an important outcome variable after total knee arthroplasty (TKA). This may be compounded by a pre-existing fixed flexion deformity (FFD). We therefore examined the long-term outcomes of patients with a flexion deformity undergoing TKA compared to those without a preoperative fixed flexion deformity. Participants who had undergone TKA at our centre between 1989 and 2002 were examined preoperatively, one, five and ten years after TKA (Kinemax PS; Howmedica, Rutherford, NJ, USA). Examining those with a preoperative FFD of greater than ten degrees with complete ten year follow-up data revealed 77 individuals. Seventy seven age, sex and body mass index matched patients were identified and the effect of TKA on indices of knee function (fixed flexion, maximum flexion, total ROM and Knee Society score (KSS) in both groups were analysed using repeated measures ANOVA. A significant difference between the groups with respect to fixed flexion (p < 0.001), total ROM (p = 0.001) and KSS (p < 0.001) was observed between baseline and year one suggesting that those with a preoperative FFD improved more than those without. A significant difference with regard to fixed flexion was also observed between years one to five (p = 0.001) and just failed to reach statistical significance between five to ten years (p = 0.052) between the groups. This study demonstrates that patients with a preoperative fixed flexion deformity show continued improvement in their fixed flexion up to ten years post arthroplasty and have similar outcomes to those with no preoperative fixed flexion.     

Flexion of the knee increases the distance between the popliteal artery and the proximal tibia: MRI measurements in 15 volunteers

We determined which angle of flexion best prevents popliteal artery injury during knee surgery. We took MRIs of the knee in the lateral position with the knee in 0 degrees, 45 degrees, 90 degrees, and 120 degrees of flexion in 15 volunteers. The shortest distance between the posterior cortex of the tibia and the popliteal artery was measured at various levels from the knee joint to 60 mm distally. At the level of the joint and 15 mm distally, the distance between the tibia and artery increased with increasing knee flexion. More distally, no significant difference was noted with increasing flexion. Flexion of the knee may minimize injury to the popliteal artery in procedures between the level of the joint and 15 mm distal to the joint.     

Sural artery pseudoaneurysms after knee arthroscopy: treatment with transcatheter embolization

Vascular injury of the popliteal artery or its branches after knee arthroscopy is a rare but potentially devastating complication. We report two cases of sural artery branch pseudoaneurysms resulting from knee arthroscopy. Both patients were successfully treated with transcatheter embolization of the pseudoaneurysms. the diagnosis and treatment options of this unusual injury are discussed.     

Lengthening and transfer of hamstrings for a flexion deformity of the knee in children with bilateral cerebral palsy: technique and preliminary results

Between July 2000 and April 2004, 19 patients with bilateral spastic cerebral palsy who required an assistive device to walk had combined lengthening-transfer of the medial hamstrings as part of multilevel surgery. A standardised physical examination, measurement of the Functional Mobility Scale score and video or instrumented gait analysis were performed pre- and post-operatively. Static parameters (popliteal angle, flexion deformity of the knee) and sagittal knee kinematic parameters (knee flexion at initial contact, minimum knee flexion during stance, mean knee flexion during stance) were recorded. The mean length of follow-up was 25 months (14 to 45).Statistically significant improvements in static and dynamic outcome parameters were found, corresponding to improvements in gait and functional mobility as determined by the Functional Mobility Scale. Mild hyperextension of the knee during gait developed in two patients and was controlled by adjustment of their ankle-foot orthosis. Residual flexion deformity > 10 degrees occurred in both knees of one patient and was treated by anterior distal femoral physeal stapling. Two children also showed an improvement of one level in the Gross Motor Function Classification System.     

膝关节周围骨折脱位合并腘动脉损伤

[目的]回顾性分析膝关节周围骨折、膝关节脱位合并胭动脉损伤的早期诊断、治疗。[方法]自1998年3月～2005年5月，共收治膝关节周围骨折、脱位合并有胭动脉损伤患者71例，通过临床检查、血管造影或（和）Doppler检查，及早明确诊断，及时手术探查，修复损伤的动脉、采用简单、快捷、可靠的方法稳定骨折，术后抗凝、解痉、预防感染治疗。[结果]15例伴有严重的小腿软组织毁损初期截肢，其余56例手术成功修复。骨折采用带锁髓内钉固定、钢板螺钉固定或外支架固定。术后吻合口处发生血栓形成2例，经Doppler检查证实后急诊切除血栓部，取自体大隐静脉逆转移植吻合成功。2例发生骨髓炎（均为开放性骨折），经病灶清除庆大霉素骨水泥链珠植入等处理后愈合。2例发生创伤性膝关节炎。其余骨折愈合良好，肢体功能恢复较好。[结论]膝关节周围骨折、脱位应高度怀疑合并有胭血管损伤，通过仔细临床检查，必要时结合Doppler、血管造影尽早明确诊断，及早手术探查修复损伤的血管，稳定骨折。     

Anatomic study of the middle genicular artery

PURPOSE: To study the anatomy of the middle genicular artery and thus mitigate the risk of vascular injury in knee surgery. METHODS: The course, anatomic relations, and variations of the middle genicular artery in 8 cadavers (4 men and 4 women) were studied. RESULTS: The middle genicular artery originated from the anterolateral surface of the popliteal artery in the popliteal fossa, 3 to 5 cm proximal to the joint line either alone or having a common origin with the lateral genicular artery. Its diameter varied from 2 to 4 mm and it was 3 to 5 cm long. It was accompanied by 2 venae comitantes. This vascular bundle, including the middle genicular artery, ran distally, anterior to the popliteal artery, and posterior to the joint capsule, sandwiched between them. Distally it pierced the posterior joint capsule and became intra-articular. The relation of the middle genicular artery to the popliteal artery altered with the position of the knee joint. This alteration was secondary to the distal gliding of the popliteal artery with knee flexion. The middle geniculate artery formed an angle of 15 to 30 degrees to the popliteal artery when the knee was extended, which became almost a right angle when the knee was flexed past 90 degrees. CONCLUSION: Care must be taken when arthroscopic or open intra-articular surgery is performed in the posterior part of the knee joint using chondrotomes and saws, particularly with limited vision. Sharp dissection and diathermy under direct vision should be safer.     

Posterolateral dislocation of the knee joints：analysis of 9 case

Objective:To analyze the rtraumatie pathologieal characteristics of posterolateral dislocation of knee joins and its treatment.Methods:Mine cases of posterolateral dislocation of knee joint,5 cases of fresh injuries(the fresh injury group)and 4 cases of old injuries (the old injury group)were reviewed and analyzed.In the fresh injury group 4 cases failed in close reduction due to “buttonholing”through the medial joint,among them 3 case underwent repair of the damaged ligantents.In the old injury group 2 cases underwant ACL and MCL repair only in acuts stage,but re-dislocated.Of the rest 2 case 1 was associated with peroneal nerve injury and the other was not treated of the tibiul condyle and popllteal artery injury.Open reduction was performed in 3 enses.One case was fixed with 2-crossed pin and another was fixed with one pin through the tibial and femoral condyle and second pin with olecranization fixation.Plester immobilization for 6.8 weeks respectively was required.In the old injury group in 1 case ACL and PCL repair(Augustine method) and posterolateral structure were performed and olecranization fixation and plaster immobilization for 6 weeks was needed.Arthrodesis of the knee was done for the patient with comminuted fracture of the tibial condyte and popliteal artery injury.Results:All the cases were followed up for 1-23 years(average 6 years).Knee stabllity in 4 cases with repair of the ligaments was improved,although PDT showed ( ) with different was improved,although the patients treated with ligamentous reconstruction were much better than those of the patients without any repair. Conclusions:Well understanding of the tranmatic pathological characteristics,repair of the damaged postoperative immobilization for 6 weeks are the key points of successful treatment.     

The role of hamstring tightness in plantar fasciitis

BACKGROUND: Plantar fasciitis is a repetitive microtrauma overload injury of the attachment of the plantar fascia at the inferior aspect of the calcaneus. Several etiological factors have been implicated in the development of plantar fasciitis; however, the role of hamstring tightness has not been evaluated. METHODS: Fifteen volunteers (mean age 32.6 +/- 4.7 years) were prospectively analyzed for differences in forefoot loading using a Don-Joy brace (dj Orthopedics, Vista, CA) applied to each knee simultaneously. The brace was locked at varying degrees of knee flexion (0 degrees, 20 degrees, and 40 degrees). Their mean popliteal angle was 6.5 degrees. Fifteen patients (mean age 40 +/- 16.5 years) with a diagnosis of chronic plantar fasciitis were similarly analyzed on the pedobarograph. These patients also had their hamstring tightness evaluated by measuring the popliteal angle. The mean popliteal angle was 23 degrees. RESULTS: Increasing the angle of flexion from 0 to 20 degrees at the knee joint led to a statistically significant increase in pressure in the forefoot phase by an average of 0.08 K/cm(2)s (p < 0.05). An increase from 20 to 40 degrees led to increased forefoot phase pressure of 0.08 kg/cm(2)s (p < 0.05). The percentage of time spent in contact phase decreased from 35.37% to 30.87% to 26.37% with increasing flexion (p < 0.05). However there was an inverse increase in the time spent in the forefoot phase 46.6% to 55.6 to 61.25% with increasing degrees of flexion (p < 0.05). CONCLUSION: The results indicate that an increase in hamstring tightness may induce prolonged forefoot loading and through the windlass mechanism be a factor that increases repetitive injury to the plantar fascia.     

人工全膝关节置换术治疗膝关节伸直位强直畸形

目的探讨膝关节伸直位强直畸形患者行人工全膝关节置换术的手术要点和术后效果。方法1996年1月至2006年6月,对8例（9膝）膝关节伸直位强直畸形患者行人工全膝关节置换术。术前膝关节活动度均为0°,KSS膝关节评分平均为44分（10～68分）,功能评分平均为17分（-10～55分）。结果8例患者（9膝）围手术期出现的并发症包括髌腱止点撕脱1膝,髌骨下极部分撕脱骨折1膝,术后早期关节血肿1膝,皮肤浅表性感染1膝,经对症治疗后所有患者均治愈出院。术后平均随访40．4个月（7．0～120．0个月）,术后膝关节平均活动度89°（50°～120°）,术后KSS膝关节评分平均为81分（55～93分）,功能评分平均为79分（50～90分）。2例2膝分别存在5°和25°的伸展滞缺。1例1膝因为关节不稳于术后1年行翻修术,更换加厚的胫骨平台垫片。结论膝关节伸直位强直畸形患者行人工全膝关节置换术难度大,并发症发生率较高,但如能恰当处理,仍可以取得较满意的临床效果。术中膝关节的充分暴露,保留足够的髌骨床厚度,保护髌腱和膝关节的血液供应以及正确的软组织平衡技术是手术的关键。     

Popliteal vessels in knee surgery. A magnetic resonance imaging study.

Popliteal artery injury during surgery of the knee is rare but can have devastating consequences. The position of knee flexion has been thought to be protective for the popliteal artery, allowing it to fall back from the knee joint. No prior study has provided in vivo cross sectional evidence of the behavior of the popliteal vessels during knee flexion with the effect of gravity. Magnetic resonance imaging was used in nine volunteers to measure the distance of the popliteal artery and veins from the posterior proximal tibia at two levels corresponding to the levels of osteotomy in total knee arthroplasty and in high tibial osteotomy. Scans were taken with the knee in full extension and at 90 degrees flexion with the patient in the supine position, allowing for the effect of gravity. Considerable variation in behavior of the vein and the artery was observed at the high tibial osteotomy cross sectional level and the total knee arthroplasty cross sectional level. In two knees at the high tibial osteotomy cross sectional level and in two knees at the total knee arthroplasty cross sectional, level the artery moved closer to the posterior tibia with knee flexion. Even with the effect of gravity included, knee flexion does not guarantee removal of the popliteal vessels from potential harm during surgery of the knee.     

Excision for the treatment of periarticular ossification of the knee in patients who have a traumatic brain injury.

BACKGROUND: Patients who are comatose after a traumatic brain injury often have heterotopic periarticular ossification that can be treated with excision to improve the range of motion of the joint. METHODS: Areas of periarticular ossification were resected at an average of twenty-three months after recovery from a coma in seven knees of five patients who had a traumatic brain injury. Before the procedure, all of the knees were fixed in a flexed position that ranged from 10 to 40 degrees and they had a painful arc of motion that ranged from 20 to 70 degrees of flexion. None of the patients could walk, and some of them could barely sit in a wheelchair. At the end of the operation, the arc of motion was markedly improved in all of the knees (0 to 130 degrees in three knees, 0 to 120 degrees in three, and 10 to 120 degrees in one). In an attempt to prevent postoperative loss of motion and recurrence of the ossification, continuous passive motion was applied to the involved knee for six weeks before a full rehabilitation program was started. The latest follow-up evaluation was at an average of thirty-four months (range, twenty-five to sixty months). RESULTS: At the time of follow-up, all of the patients could walk and all of the knees were pain-free. One knee had an arc of flexion of 0 to 90 degrees; two, an arc of 10 to 100 degrees; one, an arc of 5 to 110 degrees; two, an arc of 0 to 120 degrees; and one, an arc of 0 to 130 degrees. Ossification did not recur in any of the knees. CONCLUSIONS: Patients with good neuromuscular control had the best general functional result. The routine use of a continuous-passive-motion machine was associated with no recurrence of ossification, and there was some late loss of motion after its use was discontinued.     

Functional results after surgical repair of quadriceps tendon rupture

We present the long-term results of surgical repair of a traumatic rupture of the quadriceps tendon in a group of 24 patients with a mean age of 58 years. There were 21 male and 3 female patients. Fifteen patients were seen for clinical control after a mean follow-up of 75 months and they all presented with some quadriceps muscle atrophy. Twelve patients had normal knee mobility, three had a flexion deformity of 10 degrees and two had less than 120 degrees of knee flexion. Active knee extension was normal in all patients. Three patients experienced some decrease in stability of their knee joint. Subjectively all patients were satisfied with the result. Nine patients underwent a Cybex-test for evaluation of the isokinetic force of knee flexion and extension, with a comparison between the injured and the uninjured side. For concentric force there was a mean deficit at low speed of 36.1% for the quadriceps muscle; at high speed it was 28.2%. For the knee flexors, the deficits were 30.7% and 27.2% respectively. Regarding eccentric force, the mean deficit for knee extensors was 13.8% and 0.25% respectively and for knee flexors 6.5% and 5.5% respectively.     

FUNCTIONAL POPLITEAL ENTRAPMENT SYNDROME

Background : Classic popliteal artery entrapment is caused by the abnormal relationship between the popliteal artery and the medial head of the gastrocnemius, resulting in repetitive arterial compression and trauma. There is, however, a distinct subset of calf claudicants who have an anatomically normal popliteal fossa but can occlude the popliteal artery by repetitive vigorous exercise which involves active plantar flexion with or without extension at the knee joint. Methods : Eight patients who led a vigorous athletic lifestyle were evaluated with duplex scan and biplane angiogram after being referred for bilateral calf claudication. They were found to have significant stenosis or occlusion of the popliteal artery with active plantar flexion. All patients had transection of the medial head of the gastrocnemius muscle with release of any vascular bands tethering the popliteal artery. Results : Seven of the eight patients had complete relief. One patient noticed return of claudication at long distances, but a postoperative angiogram was normal. In all patients postoperative duplex scan showed no stenosis or occlusion of the popliteal vessels with the foot in active plantar flexion and the knee in extension. Conclusions : Functional popliteal artery entrapment is becoming a significant cause of disabling claudication in young athletic individuals and needs to be diagnosed accurately for appropriate treatment. This condition is becoming well known with the incorporation of sports in the daily routine of most young people.     

The position of the popliteal artery in the arthritic knee.

We studied the position of the popliteal artery in 32 patients with primary osteoarthritis of the knee. A total of 45 knees were studied using a noninvasive technique with color-flow duplex scanning. The distance between the popliteal artery and the posterior tibial cortex was measured in various positions of flexion. The distance separating them was found to be maximal between 60 degrees and 90 degrees. The study was repeated in a smaller series of 17 patients (20 knees) after knee replacement but with less conclusive results. We believe the safest position on which to operate in primary arthroplasty is with the knee in flexion, but the safety margins are not the same in revision surgery.     

Posterolateral dislocation of the knee joints:analysis of 9 cases

Posterolateraldislocationofthekneejointisrare .Till 1981,only 2 7caseswerereportedinEnglishliteratures1andnocaseswerereportedafterwards.2 ,3Thiskindofinjuryislikelymisdiagnosedasligamentdisruptionorirreducibledislocationdueto”buttonholing”ofthe jointmedially4 (Fig .1 1)Between 1979and 2 0 0 19casesofposterolateraldislocationofkneejointsweretreatedinourhospital.The pathologicalcharacteristics ,complicationsandtreatmentareanalyzedanddescribedinthispaper .Fig .1 1.Buttonholingoffemoralmedialc…     

Flexion of the knee increases the distance between the popliteal artery and the proximal tibia: MRI measurements in 15 volunteers

We determined which angle of flexion best prevents popliteal artery injury during knee surgery. We took MRIs of the knee in the lateral position with the knee in 0°, 45°, 90°, and 120° of flexion in 15 volunteers. The shortest distance between the posterior cortex of the tibia and the popliteal artery was measured at various levels from the knee joint to 60 mm distally. At the level of the joint and 15 mm distally, the distance between the tibia and artery increased with increasing knee flexion. More distally, no significant difference was noted with increasing flexion. Flexion of the knee may minimize injury to the popliteal artery in procedures between the level of the joint and 15 mm distal to the joint.     

Flexion of the knee increases the distance between the popliteal artery and the proximal tibia: MRI measurements in 15 volunteers

We determined which angle of flexion best prevents popliteal artery injury during knee surgery. We took MRIs of the knee in the lateral position with the knee in 0°, 45°, 90°, and 120° of flexion in 15 volunteers. The shortest distance between the posterior cortex of the tibia and the popliteal artery was measured at various levels from the knee joint to 60 mm distally. At the level of the joint and 15 mm distally, the distance between the tibia and artery increased with increasing knee flexion. More distally, no significant difference was noted with increasing flexion.

Flexion of the knee may minimize injury to the popliteal artery in procedures between the level of the joint and 15 mm distal to the joint.     

膝关节牵伸技术治疗先天性多发性关节挛缩症屈膝畸形

目的　探讨用膝关节牵伸技术 (Ilizarov)治疗先天性多发性关节挛缩症屈膝畸形的方法及疗效。方法　 1998年 8月至 2 0 0 3年 2月收治先天性多发性关节挛缩症 6例 ,其中双膝 4例 ,共 10个膝关节。男 5例 ,女 1例 ,年龄 3岁 7个月至 13岁 ,平均年龄 8岁 2个月。术前屈膝畸形程度平均5 1° ,合并肢体其它部位畸形 13个。应用改良Ilizarov膝关节牵伸器 ,手术安装牵伸器时 ,应维持膝关节于最大伸展位 ,牵伸器的关节铰链对准膝关节的旋转中心 ,于膝上下股骨和胫骨各穿 2组 2mm克氏针与牵伸器上下的钢环固定。术后 5d旋转延长膝后的螺纹牵伸杆 ,第 1周 2～ 3mm/d ,第 2周后改成 1～ 2mm/d ,直至达到膝关节伸直到 0°位。合并髋、足关节畸形者 ,同期或第二期实施手术矫正。本组术后膝关节牵伸时间 2 3～ 4 8d ,平均 37d ,治疗期间患肢可负重锻炼 ,停止牵伸 2周后拆牵伸器再装支具行走。结果　 10个膝关节屈曲畸形完全矫正 ,无严重并发症 ,其中 9个膝术后随访平均 1年 3个月 ,畸形无复发 ,患者行走功能显著改善。结论　Ilizarov技术治疗先天性多发性关节挛缩症屈膝畸形 ,方法简单、安全 ,效果确实 ,符合生物学原理和微创外科的原则     

Soft tissue release for knee flexion contracture in juvenile chronic arthritis

Twenty-nine soft tissue releases for knee flexion contracture were performed in 23 children 2-15 years of age with juvenile chronic arthritis. The average duration of knee joint involvement was 4.6 years (range 1-11 years), and the mean age at operation was 8.6 years. Twenty-one of the 29 knee joints had a fixed flexion deformity exceeding 15 degrees preoperatively. Twenty-five knees were followed up for a mean period of 3.9 years (range 1-8 years), at which time only eight knees had a flexion deformity exceeding 15 degrees. There was a lasting effect of the release operations, and no significant complications were encountered. It is concluded that the procedure is worthwhile.