Proximal tibial varus osteotomy. Indications, technique, and five to twenty-one-year results

BACKGROUND: Although high tibial osteotomy has been proved effective for the treatment of painful osteoarthritis of the medial compartment of the knee, the role of proximal tibial varus osteotomy for the treatment of painful osteoarthritis of the lateral compartment still remains controversial. METHODS: From 1974 to 1993, we performed proximal tibial varus osteotomy for the treatment of osteoarthritis of the lateral compartment of the knee in thirty-six consecutive patients. The procedure consisted of a proximal lateral opening-wedge varus osteotomy of the tibia with use of corticocancellous bone grafts from the iliac crest. The valgus deformity was posttraumatic in twenty-three patients, followed a lateral meniscectomy in five, was due to overcorrection of a varus deformity in four, and was idiopathic in four. The preoperative valgus deformity averaged 11.6 degrees (range, 4 degrees to 22 degrees ). RESULTS: At a mean of eleven years (range, five to twenty-one years) after the operation, the clinical results for thirty-four of the thirty-six patients were analyzed. None of the patients had severe progression of the osteoarthritis after the osteotomy, and none had a meaningful loss in the range of motion of the knee joint. A superficial wound infection developed in one patient, and another patient had thrombophlebitis. Three patients (9%) had a transient palsy of the peroneal nerve. According to the system of Insall et al., the mean knee score was 84 points (range, 54 to 99 points). According to the knee score described by Lysholm and Gillquist, the subjective result was excellent in nine patients (26%), good in twenty-one (62%), fair in three (9%), and poor in one (3%). CONCLUSIONS: We concluded that when the indications outlined in this study are followed and our opening-wedge technique is used, a proximal lateral opening-wedge varus osteotomy of the tibia is a good alternative for the treatment of isolated osteoarthritis of the lateral compartment of the knee. High accuracy in preoperative planning, based on a slight overcorrection, is important to prevent failure.     

Optimizing femorotibial alignment in high tibial osteotomy.

OBJECTIVE: To study factors that affect femorotibial (F-T) alignment after valgus closing wedge tibial osteotomy. STUDY DESIGN: A review of standardized standing radiographs. Femorotibial alignment was measured 1 year postoperatively for over- and under-correction. Changes in F-T alignment and in tibial plateau angle were measured. SETTING: An urban hospital and orthopedic clinic. PATIENTS: Eighty-two patients with osteoarthritis and varus femorotibial alignment underwent valgus closing wedge tibial osteotomy. Patients having a diagnosis of inflammatory arthritis or a prior osteotomy about the knee were excluded. RESULTS: A 1 degree wedge removed from the tibia resulted in an average correction F-T alignment of 1.2 degrees. A knee that had increased valgus orientation of the distal femur had a greater degree of correction, averaging 1.46 degrees in F-T alignment per degree of tibial wedge. This resulted in excessive postoperative valgus alignment for some patients who had increased valgus tilt of the distal femur. Optimal F-T alignment of 6 degrees to 14 degrees valgus occurred when the postoperative tibial inclination was 4 degrees to 8 degrees of valgus. CONCLUSIONS: There was a trend for knees with increased valgus orientation of the distal femur to have greater correction in F-T alignment after tibial osteotomy, likely because of a greater opening up of the medial joint space during stance. Surgeons need to account for this in their preoperative planning.     

Tibial condylar valgus osteotomy (TCVO): Surgical technique and clinical results for knee osteoarthritis with varus deformity

Tibial condylar valgus osteotomy (TCVO) is an intra-articular proximal tibial osteotomy developed in 1989 and has since been used for the treatment of knee osteoarthritis (OA) associated with genu varum. This article describes the surgical technique and clinical results of TCVO. TCVO can be used for all grades of varus knee OA in patients of any age. he preoperative range of movement should be at least 90°. Preoperative screening showed varus-valgus instability due to an intra-articular deformity of the proximal tibia. Using intraoperative image intensification, a sagittally oriented “L”-shaped osteotomy is made from the medial to the tibial tuberosity to the center of the tibial plateau between the medial and lateral tibial spines. The separation of the osteotomy using the lamina spreader is gradually increased using an image intensifier guidance until the articular surface of the lateral tibial plateau comes in contact with the articular surface of the lateral femoral condyle. Adequate correction is indicated by parallelism of the lateral tibial plateau and a line tangential to the distal convexity of the lateral femoral condyle on an anteroposterior (AP) image and the elimination of the valgus instability with the knee in extended position. A “T”-plate (locking or non-locking plate or circular external fixator) is used to fix the osteotomy in the corrected position. Synthetic or autologous bone grafts can be used. We used the Japanese Orthopaedic Association score to evaluate the patient's function and also measured the %MAD, medial plateau opening angle, medial plateau angle, and lateral plateau opening angle on an AP view of the long length roentgenogram of the lower limb (standing position). The JOA score, radiologically measured values, and instability of the knee joint remarkably improved.     

Treatment for painful bone marrow edema by open wedge tibial osteotomy

We evaluated the results of patients who had undergone medial open wedge proximal tibial osteotomy, with painful bone marrow edema in the medial tibial plateau. The study included 21 patients who had presented with knee pain and whose MRIs showed bone marrow edema in medial plateau. The degree of osteoarthritis was evaluated radiologically according to the Kellgren–Lawrence criteria; 6 cases were Grade 1, 11 cases were Grade 2, and 3 cases were Grade 3. Preoperative varus angle was a mean of 2.19° (0–4). The bone marrow edema was classified according to the width of the lesions extending into the joint surface subchondral area on MRI T2 sequences. Open wedge osteotomy was performed in all patients. The postoperative results were evaluated by X-ray, MRI, and WOMAC (Western Ontario and McMaster Universities) knee scores. The preoperative 2.19° varus angle was evaluated postoperatively as valgus 6.57° (4–8°) (p < 0.05). The postoperative WOMAC knee scores revealed a significant decrease in pain (p < 0.05). In conclusion, we are of the opinion that medial open wedge proximal tibial osteotomy is an effective treatment in patients who have painful bone marrow edema in medial tibia plateau.     

胫骨内侧高位楔形截骨治疗膝关节骨性关节炎

目的　探讨胫骨内侧高位楔形截骨治疗伴有膝内翻畸形的膝关节骨性关节炎的疗效。方法　对 1996年 7月～ 1999年 9月 ,采用胫骨内侧高位楔形截骨结合髂骨植骨钢板内固定术治疗 19例 (2 6膝 )膝关节骨性关节炎伴膝内翻畸形 ,病程 1～ 2 4年 ,平均 6 .3年 ,按 Ahlback分类 度 10膝 , 度 9膝 , 度 6膝 , 度 1膝。患者术前、术后 8周和术后 2年进行患肢全长 X线片检查 ,测量胫股角、胫骨角、股骨角、胫股关节面切线夹角及胫股内侧关节间距大小。按膝关节功能评定标准 ,评定术后膝关节功能恢复情况。　结果　 19例 (2 6膝 )术后获随访 2 4～ 4 5个月 ;术后 2年随访膝关节功能自 (4 8.6± 16 .6 )分增至 (81.7± 14 .8)分 ,胫股内侧关节间距自 (2 .2± 1.6 ) mm增至 (4 .9± 1.5 ) mm,胫股关节面切线夹角自 7.4°± 3.1°减少至 1.7°± 3.1°。植骨愈合满意 ,无膝内翻复发。术中出现关节内骨折 1例 ;皮肤感染 2例。结论　胫骨内侧高位楔形截骨结合植骨钢板内固定 ,可作为治疗伴有膝内翻畸形的膝关节骨性关节炎的有效方法之一。     

Fixation stability following high tibial osteotomy: a radiostereometric analysis

Fifteen patients with varus gonarthrosis underwent high tibial osteotomy and internal fixation with an L-shaped rigid plate. In 9 patients, an average wedge size of 7.1 degrees was resected leaving the medial cortex of the proximal tibia intact (group 1). In 6 patients, the medial cortex of the proximal tibia was unintentionally fractured during surgery when an average 10.7 degrees wedge was resected (group 2). Postoperatively, patients were monitored with serial radiostereometric analysis (RSA), conventional radiographs, and clinical evaluation for 1 year. In group 2, RSA revealed a 1.3-mm increase in lateral displacement of the distal tibial segment within 3 weeks following surgery. Twelve weeks after surgery, micromotion between tibial segments was below the precision of the RSA setup in 14 of 15 patients. These findings indicate that in cases with larger wedge sizes (>8 degrees), fracture of the medial cortex of the proximal tibia was frequent and resulted in significant lateral displacement of the distal tibia relative to the tibial plateau. In such cases, prophylactic additional medial fixation rather than lateral L-plate fixation alone is advised to minimize the propensity for lateral displacement of the distal tibia and to avoid subsequent loss of correction.     

Observations on patellar height following opening wedge proximal tibial osteotomy

Patellar height and patellar ligament length were assessed pre- and postoperatively in 28 patients who underwent a medial opening wedge proximal tibial osteotomy for varus gonarthrosis. This procedure produced no significant change in patellar ligament length. Pre- and postoperative Insall-Salvati ratios were 0.96+/-0.12 and 0.97+/-0.15, respectively (P=.30). The Insall-Salvati ratio decreased in 29% of patients, and no patient experienced a decline >0.07. The distance between the patella and tibiofemoral joint line ("patellar height") decreased in 100% of patients. The mean Blackburne-Peel ratio declined from 0.75+/-0.13 to 0.53+/-0.15 (P<.001). Sixty-four percent of the postoperative Blackburne-Peel values satisfied the radiographic criterion for patella infera (Blackburne-Peel ratio <0.54). Whereas the loss of patellar height, historically associated with lateral closing wedge proximal tibial osteotomy, is a function of patellar ligament contracture, the decreased distance between the patella and the tibiofemoral joint line following medial opening wedge proximal tibial osteotomy is a function of joint line elevation. The high incidence of patella infera following medial opening wedge proximal tibial osteotomy may have deleterious effects on patellofemoral biomechanics or may complicate subsequent total knee arthroplasty.     

Infantile tibia vara: Treatment of Langenskiold stage IV

An eight year old girl presented with a progressively increasing deformity of the left proximal tibia since last 2 years. She had no history of trauma, fever and swelling of left knee. There were no obvious signs of rickets/muscular dystrophy. She had 25 degrees of tibia vara clinically with lateral thrust and a prominent fibular head. The radiograph of left knee revealed tibia vara with medial beaking and a significant depression of the medial tibial epiphysis and metaphysis. A computed tomography (CT) scan revealed significant depression of the medial tibial epiphysis but no bony bar in the physis or fusion of the medical tibial epiphysis. There was a posterior slope in addition to the medial one. She was treated with elevation of the medial tibial hemiplateau with subtuberosity valgus derotation dome osteotomy. She also underwent a lateral proximal tibial hemiphysiodesis (temporary stapling). A prophylactic subcutaneons anterolateral compartment fasciotomy was also performed. All osteotomies united in 2 months. All deformities were corrected and she regained a knee range of 0 to 130 degrees. At final followup (4 years), there was no recurrence of varus deformity, knee was stable, with 1cm of leg length discrepancy. In Langenskiold stage IV tibia vara, elevation of medial tibial plateau, a subtuberosity valgus derotation osteotomy and a concomitant lateral hemiephiphysiodesis has given good results.     

Autogenous bone grafting for severe angular deformity in total knee arthroplasty

Fourteen patients with severe angular knee deformities (range, 30 degrees varus to 35 degrees valgus) had total knee arthroplasty using autogenous bone graft to the tibia. Twelve knees had osteoarthritis, one rheumatoid arthritis, and one gouty arthritis. The preoperative knee motion averaged -5 degrees of extension to 80 degrees of flexion and the average motion arc was 70 degrees. All tibial defects were greater than 25% of the tibial component support surface and more than 10 mm deep. Twelve knees were reconstructed with Insall-Burstein posterior stabilized total condylar knee implants and two knees, with severe preoperative ligamentous instability, with the constrained Total Condylar III implant. Postoperative rehabilitation was routine, and weight bearing was begun, on average, on the third postoperative day. The follow-up period averaged 4.1 years (range, 2-7.3 years). Radiographic analysis revealed no change in knee or component alignment compared with immediate postoperative position. All grafts consolidated without evidence of collapse, resorption, or prosthetic subsidence. All patients had good or excellent clinical results (Hospital for Special Surgery Knee Rating Scale). The average postoperative arc of motion was 90 degrees. There were no infections and no need for implant removal. The technique developed by the senior author (T.P.S.) utilizes bone resected from the distal femur during knee arthroplasty. An oblique planar cancellous surface is created on the recipient side, and coaptation of cancellous distal femoral graft surface to this recipient bed is ensured by vitallium screw fixation. The proximal tibia is reconstituted by the graft, and subchondral femoral bone after shaping of the graft forms the tibial periphery.     

Implementation, accuracy evaluation, and preliminary clinical trial of a CT-free navigation system for high tibial opening wedge osteotomy.

OBJECTIVE: The objectives of this study are to design and evaluate a CT-free intra-operative planning and navigation system for high tibial opening wedge osteotomy. This is a widely accepted treatment for medial compartment osteoarthritis and other lower extremity deformities, particularly in young and active patients for whom total knee replacement is not advised. However, it is a technically demanding procedure. Conventional preoperative planning and surgical techniques have so far been inaccurate, and often resulting in postoperative malalignment representing either under- or over-correction, which is the main reason for poor long-term results. In addition, conventional techniques have the potential to damage the lateral hinge cortex and tibial neurovascular structures, which may cause fixation failure, loss of correction, or peroneal nerve paralysis. All these common problems can be addressed by the use of a surgical navigation system. MATERIALS AND METHODS: Surgical instruments are tracked optically with the SurgiGATE((R)) navigation system (PRAXIM MediVision, La Tronche, France). Following exposure, dynamical reference bases are attached to the femur, tibia, and proximal fragment of the tibia. A patient-specific coordinate system is then established, on the basis of registered anatomical landmarks. After intra-operative deformity measurement and correction planning, the osteotomy is performed under navigational guidance. The deformities are corrected by realigning the mechanical axis of the affected limb from the diseased medial compartment to the healthy lateral side. The wedge size, joint line orientation, and tibial plateau slope are monitored during correction. Besides correcting uni-planar varus deformities, the system provides the functionality to correct complex multi-planar deformities with a single cut. Furthermore, with on-the-fly visualization of surgical instruments on multiple fluoroscopic images, penetration of the hinge cortex and damage to the neurovascular structures due to an inappropriate osteotomy can be avoided. RESULTS: The laboratory evaluation with a plastic bone model (Synbone AG, Davos, Switzerland) shows that the error of deformity correction is <1.7 degrees (95% confidence interval) in the frontal plane and <2.3 degrees (95% confidence interval) in the sagittal plane. The preliminary clinical trial confirms these results. CONCLUSION: A novel CT-free navigation system for high tibial osteotomy has been developed and evaluated, which holds the promise of improved accuracy, reliability, and safety of this procedure.     

Upper tibia osteotomy: long term results — realignment analysis using OASIS computer software

BACKGROUND: The normal values for axial alignment and joint line obliquity of the knee that indicate a successful valgus upper tibial osteotomy have not been established and reported in the literature. METHODS: To identify those parameters we prospectively followed 51 patients with 54 lateral closing wedge upper tibial osteotomies performed after preoperative and postoperative analysis of standardized hip-to-ankle radiographs with a software computer program (OASIS). RESULTS: Of the 54 knees, 18 (33.3%) underwent additional surgery. The average follow-up of the remaining 36 knees was 10 years (range 6.9-13.8 years). The cumulative osteotomy survival rate was 89% at 5 years and 76% at 10 years. Compared with patients whose postoperative femorotibial angle was 174 degrees -180 degrees , the patients whose postoperative femorotibial angle was <174 degrees or >180 degrees did worse with respect to osteotomy failure. Ten knees were at a decreased risk of failure. These knees had a postoperative femorotibial angle of 174 degrees -180 degrees , lateral joint line obliquity of <4 degrees , and a medial plateau force distribution of 40%-60%. The knees that met these criteria had 100% survival at 5 and 10 years, whereas the rest of the knees had survival rates of 86% and 70%, respectively. CONCLUSIONS: We believe that using these criteria during preoperative planning may improve the survival of upper tibial osteotomy provided a precise, reproducible surgical technique and rigid fixation can be performed.     

Editorial Commentary: Avoid Creating an Oblique Joint Line After an Opening Medial Wedge High Tibial Osteotomy

A medial opening wedge high tibial osteotomy is a cost-effective procedure for younger patients with symptomatic medial compartment knee arthritis. A high rate of success can be expected, but excessive postoperative joint line obliquity is associated with inferior clinical outcomes. If preoperative planning predicts that the postoperative medial proximal tibial angle, the medial angle between the tibial anatomical axis and the joint line of the proximal tibia, will exceed 95°, a surgeon should consider performing a double-level osteotomy (combined proximal tibial and distal femoral osteotomies).     

Editorial Commentary: Lateral Hinge Fracture in High Tibial Osteotomy: Risk or Annex?

The basic aim of the medial opening wedge high tibial osteotomy is to use the elasticity of the lateral cortex as a biomechanical stabilizer, whereas the medial opening gap is maintained by a locking plate. This surgical construct tolerates early weight bearing, free range of knee motion, and sufficient bone healing for an acceptable time. We always perform a biplanar osteotomy, which reduces risk of fracture and improves healing potential owing to more bony contact area. We take some time opening the wedge owing to the elasticity of the lateral cortex. Careless manipulation can harm your hinge! Preoperative planning regarding corrective and postoperative expected joint line angles is key. If the gap is more than 10 mm, we use autologous bone graft or substitute. Partial weight bearing is indicated for 6 weeks to reduce fracture risk. When indicated, we perform double osteotomies, at the distal femur and proximal tibia, to perfectly achieve postoperative joint angles within the intended mechanical axis goal. Fractures of the lateral hinge occur in up to 30% of cases, whereas our nonunion rate is 5.4%.     

Effect of high tibial flexion osteotomy on cartilage pressure and joint kinematics: a biomechanical study in human cadaveric knees

Introduction Valgus high tibial osteotomy is an established treatment for unicompartmental varus osteoarthritis. However, only little is known about the effect of osteotomy in the sagittal plane on biomechanical parameters such as cartilage pressure and joint kinematics. This study investigated the effects of high tibial flexion osteotomy in a human cadaver model.Materials and methods Seven fresh human cadaveric knees underwent an opening wedge osteotomy of the proximal tibia in the sagittal plane. The osteotomy was opened anteriorly, and the tibial slope of the specimen was increased gradually. An isokinetic flexion-extension motion was simulated in a kinematic knee simulator. The contact pressure and topographic pressure distribution in the medial joint space was recorded using an electronic pressure-sensitive film. Simultaneously the motion of the tibial plateau was analyzed three-dimensionally by an ultrasonic tracking system. The traction force to the quadriceps tendon which was applied by the simulator for extension of the joint was continuously measured. The experiments were carried out with intact ligaments and then after successively cutting the posterior and anterior cruciate ligaments.Results The results demonstrate that tibial flexion osteotomy leads to a significant alteration in pressure distribution on the tibial plateau. The tibiofemoral contact area and contact pressure was shifted anteriorly, which led to decompression of the posterior half of the plateau. Moreover, the increase in the slope resulted in a significant anterior and superior translation of the tibial plateau with respect to the femoral condyles. Posterior subluxation of the tibial head after cutting the posterior cruciate ligament was completely neutralized by the osteotomy. The increase in slope resulted in a significant higher quadriceps strength which was necessary for full knee extension.Conclusions We conclude from these results that changes in tibial slope have a strong effect on cartilage pressure and kinematics of the knee. Therapeutically a flexion osteotomy may be used for decompression of the degenerated cartilage in the posterior part of the plateau, for example, after arthroscopic partial posterior meniscectomy. If a valgus osteotomy is combined with a flexion component of the proximal tibia, complex knee pathologies consisting of posteromedial cartilage damage and posterior and posterolateral instability can be addressed in one procedure, which facilitates a quicker rehabilitation of these patients.Winner of the AGA-DonJoy Award 2003     

Intermediate follow-up of high tibial osteotomy: a comparison of two techniques

All high tibial osteotomies (HTOs) performed in the Royal Bournemouth Hospital from June 1987 to February 1995 were retrospectively analyzed looking at the preoperative and postoperative radiographs, preoperative and postoperative range of motion (ROM), alignment, and knee scores. Patient perception was also recorded. In all there were 68 high tibial osteotomies (HTOs), of which 40 were performed by Maquet's dome method and 28 were done by closing wedge osteotomy. Average follow up was 8.6 years (range: 5.2 to 13 years) and 16 (23.5%) cases went on to have total knee arthroplasty after an average interval of 3.7 years. The results of the two methods are compared. Average preoperative HTO alignment was a varus of 4.72 degrees and average postoperative HTO alignment was a valgus of 1.48 degrees. The average radiological grade of osteoarthritis and compartments affected was comparable in the two groups. Overall 35 (51.5%) patients were dissatisfied with their results. A larger percentage of people (57.5%) who had a Maquet's dome osteotomy were unhappy with their operation as compared to 42.9% of people who were unhappy following a closing wedge osteotomy. There was consistent undercorrection after dome osteotomy, with an average alignment of a varus of 1.45 degrees compared to a valgus of 5.67 degrees after a closing wedge procedure. The preoperative subluxation was greater in the patients with a relatively poor result, 3.86 mm compared to 2.03 mm in those with a good result. It is felt that the rather poor results following osteotomy in this series was due to insufficient correction obtained and the advanced stage of osteoarthritis resulting in subluxation. In this series the correction obtained with closing wedge method was better than with the dome method, although it was inadequate with both methods. Although the wedges appeared to do better than the domes, this was not statistically significant. Overall, there was no significant correlation of our results with post osteotomy alignment. Preoperative lateral tibial subluxation was, however, a poor prognosticator of results.     

Posterior tibial slope in the normal and varus knee.

Posterior tibial slope was evaluated in 30 normal and 30 varus knees using magnetic resonance imaging. The mean tibial posterior slope in the medial plateau was 10.7 degrees (range: 5 degrees - 15.5 degrees) in the normal knees and 9.9 degrees (range: 1.5 degrees - 19 degrees) in the varus knees. The mean tibial posterior slope in the lateral plateau was 7.2 degrees (range: 0 degrees - 14.5 degrees) in the normal knees and 6 degrees (range: 1 degrees - 13 degrees) in the varus knees. Although these differences were not statistically significant, there was a large range in the posterior tibial slope in both groups. When 10-mm thickness of bone was resected in the middle of the lateral plateau in total knee arthroplasty, the thickness of the bone resection in the anterior and posterior part of the lateral plateau was measured. The presumed thickness of bone was 10.1 mm (range: 7.3-13.9 mm) in the anterior part and 7.5 mm (range: 5-10.3 mm) in the posterior part. A large range in the measured thickness of bone also was detected in the varus knees. These results suggest that the shape of the proximal tibia varies among individuals and that the cutting angle should be determined in each case to avoid any mismatch of the patient's posterior slope of the tibia after implantation.     

Computer aided high tibial open wedge osteotomy

High tibial osteotomy is a widely accepted treatment of medial compartment osteoarthritis as well as other lower extremity deformities. However, it is a technically demanding procedure. The lack of exact intraoperative real time control of the mechanical axis often results in postoperative malalignments, which is one reason for poor long term results. These problems can be addressed with the use of a surgical navigation system. Following exposure, dynamic reference bases (DRBs) are attached to the femur, and the proximal and the distal part of the tibia. After intraoperative measurement of the deformities and correction planning, the osteotomy is performed under navigational guidance. The wedge size, joint line orientation, and tibial plateau slope are monitored during correction. The in vitro evaluation with a plastic bone model suggests that the error of deformity correction is less than 1.7 degrees (95% confidence limits) in the frontal, and less than 2.3 degrees (95% confidence limits) in the sagittal plane, respectively. On a cadaver study of 13 legs, the mechanical axis intersected the Fujisawa line in 80.7% (range 77.5-85.8%). The preliminary clinical experience confirms these results. A novel computer tomography free navigation system for high tibial osteotomy has been developed that holds the promise of improving the accuracy, reliability, and safety of this kind of approach.     

开放楔胫骨高位截骨术对髌骨位置与关节功能的影响

目的：探讨开放楔胫骨高位截骨术对髌骨位置、膝前痛及关节功能的影响。方法：2016年6月至2021年6月,根据纳入和排除标准,共纳入采用开放楔胫骨高位截骨术治疗的膝关节内侧骨关节病患者109例（111膝）,其中男41例,女68例;年龄38～78(57.98±7.07)岁;病程1～36(8.58±6.91)个月。观察比较手术前后股胫角（femoral tibial angle,FTA）,胫骨近端内侧角（medial proximal tibial angle,MPTA）,负重位力线（weight bearing line,WBL）百分比,CD指数（Caton-Deschamps index）,髌骨外倾角（lateral patella tilt angle,LPTA）和髌骨外移（lateral patella shift,LPS）。采用Lysholm评分评价膝关节功能,视觉模拟评分（visual analogue scale,VAS）评价膝前痛程度,Kellgren-Lawrence (K-L)分级系统评价髌股关节骨关节炎进展情况。结果：109例患者获得随访,时间6～38(12.41±2....     

Comprehensive treatment of late-onset tibia vara

BACKGROUND: Late-onset tibia vara (Blount disease) can be difficult to treat because of frequent morbid obesity and associated deformities, including distal femoral varus, proximal tibial procurvatum, and distal tibial valgus, that contribute to lower extremity malalignment. We present a comprehensive approach that addresses all components of the deformity and allows restoration of the anatomic and mechanical axes. METHODS: Fifteen consecutive patients (nineteen lower extremities) with late-onset tibia vara were managed with this comprehensive approach. The mean age of the patients at the time of surgery was 14.9 years, and the mean weight was 113 kg. Standing anteroposterior and lateral radiographs were made preoperatively and at the time of the final follow-up. Preoperatively, the mean mechanical axis deviation was 108 mm, the mean lateral distal femoral angle was 95 degrees , and the mean mechanical medial proximal tibial angle was 71 degrees . In all nineteen extremities, the proximal tibial varus deformity was corrected by means of a valgus osteotomy and application of an Ilizarov ring external fixator. Distal femoral varus was corrected by means of either hemiepiphyseal stapling or valgus osteotomy with blade-plate fixation in thirteen of the nineteen extremities. Distal tibial valgus was treated either with hemiepiphyseal stapling or with varus osteotomy and gradual correction with use of the Ilizarov external fixator in eleven of the nineteen extremities. RESULTS: After a mean duration of follow-up of 5.0 years, the mean mechanical axis deviation had improved to 1 mm (range, 20 to -30 mm), the lateral distal femoral angle had improved to 87 degrees (range, 83 degrees to 98 degrees), and the mechanical medial proximal tibial angle had improved to 88 degrees (range, 83 degrees to 98 degrees ). The mean time required for correction of the proximal tibial varus deformity was thirty-one days, and the external fixator was removed at a mean of 4.5 months postoperatively. All patients had development of one or more superficial pin-track infections (mean, 1.9 pin-site infections per patient). No wound infections, nonunions, or neurovascular complications occurred. Eighteen of the nineteen extremities were pain-free at the time of the final follow-up. CONCLUSIONS: This comprehensive approach allowed restoration of the mechanical and anatomic axes of the lower extremity in patients with late-onset tibia vara, resulting in a resolution of symptoms as a result of normalization of the weight-bearing forces across the knee and ankle. We believe that this approach will decrease the risk of early degenerative arthritis of the knee.