The natural history of spontaneous osteonecrosis of the medial tibial plateau

The natural history of spontaneous osteonecrosis of the medial tibial plateau remains controversial and incomplete. We have studied 21 patients (aged between 53 and 77 years) with clinical and scintigraphic features of spontaneous osteonecrosis of the medial tibial plateau who were observed prospectively for at least three years (37 months to 8.5 years). The mean duration of follow-up was 5.6 years. The mean duration of symptoms at presentation was 4.7 weeks (3 days to 12 weeks). Radiographs of the affected knee at the first visit were normal in 15 patients and mildly arthritic in six. The characteristic radiographic lesion of osteonecrosis was noted at presentation in five of the mildly arthritic knees and during the evolution of the disease in eight of the radiographically normal knees. During the follow-up, subchondral sclerosis of the affected medial tibial plateau was noted in 16 knees. There are three distinct patterns of outcome: 1) acute extensive collapse of the medial tibial plateau in two knees within three months of onset; 2) rapid progression to varying degrees of osteoarthritis in 12 knees, in eight within a year, in all within two years and deterioration of the pre-existing osteoarthritis in three; and 3) complete resolution in four knees, two of which were normal at presentation and two mildly osteoarthritic. The two patients with acute extensive collapse and three who had rapid progression to severe osteoarthritis required total knee arthroplasty. We conclude that osteonecrosis of the medial tibial plateau progresses in most cases to significant degenerative disease of the knee.     

Management of osteonecrosis of proximal tibia using trabecular osteonecrotic rods

Osteonecrosis of the knee is a well-described cause of acute knee pain. It can lead to significant functional impairment, rapid arthritic joint changes and subsequent collapse. Several hypotheses exist different treatment options are used ranging from conservative management to joint arthroplasty. The majority of cases involve the distal femoral condyle and to a much lesser extent the medial tibial plateau.We are presenting a rare case of osteonecrosis of the proximal tibia affecting the lateral tibial condyle in 44 years old Caucasian male which was treated successfully using osteonecrotic tantalum rods with 26 month follow-up.     

Computer-Assisted Total Knee Arthroplasty for Significant Tibial Deformities

Computer-assisted total knee arthroplasty has been demonstrated to provide reproducible limb mechanical alignment within 3° from the neutral mechanical axis. However, restoring proper implant and extremity alignment remains a significant challenge with proximal tibial deficiencies. In this prospective study, we describe the use of computer navigation to quantify the amount of bone loss on the medial or lateral tibial plateau and the use of these data to assess the need for augmentation with metallic tibial wedges. In this study, we demonstrate that computer-assisted total knee arthroplasty in patients with significant tibial deformities can accurately measure severe tibial deformities, predict tibial augment thickness, and provide excellent mechanical alignment and restore the joint line without excessive bony resection, repeated osteotomies, and repeated augment trialing.     

Radial displacement of the medial meniscus in varus osteoarthritis of the knee

The macroscopic and histologic findings for 31 medial menisci and medial tibial plateaus obtained during total knee arthroplasty were examined to clarify the etiology and progression of varus osteoarthritis. Medial menisci were preserved fairly well in cases of severe osteoarthritis in which the medial joint space had already disappeared. The anterior segment was preserved in 26 (84%) menisci and the posterior segment was preserved in 11 (35%). The medial meniscus may have been preserved because of its radial displacement. Exposure of subchondral bone of the medial tibial plateau occurred in all 31 knees. The exposure of subchondral bone was centered in the anterior, middle, and posterior in nine, 10, and 12 medial tibial plateaus, respectively. There was a mechanical inconsistency between the pattern of preservation of the medial menisci and the location of exposure of subchondral bone on the medial tibial plateaus. The inconsistency reflects that the segment of the medial meniscus on which the excessive load was considered to exist was preserved fairly well. The authors' hypothesis for explaining this inconsistency is that radial displacement of the medial meniscus precedes narrowing of the medial joint space during progression of varus osteoarthritis, so that the displaced meniscus is saved from severe degeneration or attrition.     

Spontaneous Osteonecrosis of the Knee

Spontaneous osteonecrosis of the knee is a common cause of knee pain, principally seen in women over 60 years of age. This condition is distinguished from secondary conditions with known causes, such as corticosteroid-induced osteonecrosis. Although originally described and most common in the medial femoral condyle, it can also occur in the tibial plateaus and on the lateral side of the femur. The radionuclide bone scan will show focally increased uptake before the radiographs are abnormal. Magnetic resonance imaging can also be diagnostic, but the findings may be normal early in the course of the disease. The etiology remains unknown, but it is speculated that primary vascular ischemia or microfractures in osteoporotic bone are causative. Many patients have a benign course followed by resolution of symptoms. Therefore, conservative management is indicated initially. If progressive collapse accompanied by severe symptoms occurs, high tibial osteotomy, unicompartmental replacement, and total knee replacement are therapeutic alternatives. Recognition of this entity is important to avoid needless surgical intervention.     

初次全膝置换自体骨移植修复胫骨平台骨缺损

[目的]探讨初次行全膝置换术中采用自体骨移植修复严重膝内翻胫骨内侧平台骨缺损的疗效.[方法]回顾性分析2006年2月-2019年3月收治的行初次膝关节表面置换术180例严重膝内翻患者的临床资料,其中86例胫骨截骨后仍存在内侧平台骨缺损、行自体骨移植修复.总结86例患者的临床与影像结果.[结果] 86例患者均顺利完成手术...     

Total knee arthroplasty for neuropathic joint disease after severe bone destruction eroded the tibial tuberosity

This article describes a patient in whom total knee arthroplasty was performed for neuropathic joint disease secondary to diabetes mellitus after severe bone destruction eroded the tibial tuberosity. At initial examination, radiographs of the knee showed bone destruction in the medial and anterior regions of the tibia, and fine bone fragments were seen in the joint. Conservative therapy was performed using a brace. However, bone destruction gradually advanced, and 10 months after the initial examination, radiographs of the knee showed bone destruction in the lateral condyle of the femur and advanced bone destruction of the anterior tibia; the tibial tuberosity was missing. It is rare for the tibial tuberosity in the anterior tibia to disappear. If this happens, reconstruction is difficult and total knee arthroplasty becomes complicated. For the bone defect in the tibia, cement was used to recreate the shape of the anterior surface of the tibia. It was possible to minimize the volume of bone resection and morphologically reconstruct the tibial tuberosity. The patient recovered quickly. At postoperative week 5, the patient was able to walk using a cane. Thirty-six months after total knee arthroplasty, knee extension was 0°, flexion was 120°, extension lag was 5°, knee score improved from 40 points to 94 points, and functional score improved from 20 points to 75 points. However, long-term implant stability needs to be carefully monitored.     

Oxford medial unicompartmental arthroplasty for focal spontaneous osteonecrosis of the knee

BACKGROUND: Spontaneous osteonecrosis of the knee (SONK) is a distinct clinical condition occurring in patients without any associated risk factors. There is controversy as to the best method of treatment, and the available literature would suggest that patients with SONK have a worse outcome than those with primary osteoarthrosis when arthroplasty is performed.We assessed the outcome of medial unicompartmental knee arthroplasty (UKA) using the Oxford prosthesis for end-stage focal spontaneous osteonecrosis of the knee (SONK; Ahlb?ck grades III and IV). PATIENTS AND METHODS: We assessed 29 knees (27 patients) with spontaneous osteonecrosis of the knee using the Oxford Knee Score. 26 knees had osteonecrosis of the medial femoral condyle and 3 had osteonecrosis of the medial tibial plateau. All had been operated on using the Oxford Medial Unicompartmental Knee Arthroplasty (UKA). This group was compared to a similar group (28 knees, 26 patients) who had undergone the same arthroplasty, but because of primary osteoarthrosis. Patients were matched for age, sex and time since operation. The mean length of follow-up was 5 (1-13) years. RESULTS: There were no implant failures in either group, but there was 1 death (from unrelated causes) 9 months after arthroplasty in the group with osteonecrosis. The mean Oxford Knee Score in the group with osteonecrosis was 38, and it was 40 in the group with osteoarthrosis. INTERPRETATION: Use of the Oxford Medial UKA for spontaneous focal osteonecrosis of the knee is reliable in the short to medium term, and gives results similar to those obtained when it is used for patients with primary osteoarthrosis.     

Medial screws and cement: a possible mechanical augmentation in total knee arthroplasty

The purpose of this study was to determine whether screws placed beneath the medial tibial plateau in cemented total knee arthroplasty helps prevent collapse of the medial tibia. A previous study found that the AGC all-polyethylene tibial component had a 14% rate of collapse of the medial subchondral region in the first postoperative year. Of 536 implanted AGC all-polyethylene tibial components, 20 had screws inserted beneath the medial tibial plateau. No AGC all-polyethylene tibial components with screws failed because of aseptic loosening or collapse of the medial tibial plateau. The study included 125 cemented metal-backed total knee arthroplasties with screws inserted beneath the medial tibial plateau. We also found 2 cases of collapse of the medial tibial plateau and 1 case of collapse on the lateral side. No revisions were performed. The placement of screws beneath the medial tibial plateau to fill large defects is an excellent precaution against collapse of the medial tibia.     

Diagnosis and management of the osteonecrotic triad of the knee

Generalized osteonecrosis of the knee may include, in addition to osteonecrosis of the medial femoral condyle that occurs most frequently, osteonecrosis of the patella or the tibial plateau. Such involvement is known as the osteonecrotic triad of the knee. Although the clinical picture of idiopathic osteonecrosis of the medial femoral condyle seems similar to several other disorders, certain distinct features, including its typical location,clinical symptoms, and late onset of cartilaginous erosion, facilitate differential diagnosis.Despite the progress made in the diagnosis and treatment of idiopathic osteonecrosis of the medial femoral condyle, the prognosis remains severe. More than 80% of the patients deteriorate to the extent that surgical reconstruction is necessary, whereas only about 20%of the patients demonstrate spontaneous resolution or no additional deterioration of the osteonecrotic lesion.     

Spontaneous osteonecrosis of the knee: tibial plateaus

Spontaneous osteonecrosis of the medial tibial plateau is less recognized than osteonecrosis of the medial femoral condyle, but it presents in a similar manner. These patients have a sudden onset of pain on the medial side of the knee associated with a spectrum of MRI changes in the tibial subchondral bone. The small lesions can resolve with only minimal residual scar remaining in the subchondral zone. If the lesion is large, it can collapse or show MRI changes of osteonecrosis. Recognition of this problem may help avoid unnecessary intra-articular surgical intervention.     

Tuberositasosteotomie in der Knieendoprothetik

Objective

Tibial tubercle osteotomy facilitates access to the knee joint without excessive tension of the extensor apparatus with the lateral parapatellar approach and the medial parapatellar approach in case of contracture or revision arthroplasty.

Indications

Inadequate exposure of the knee joint with the lateral parapatellar approach and inadequate exposure of the knee joint with the medial parapatellar approach in case of contracture and revision arthroplasty.

Contraindications

Severe periarticular osteoporosis or bone atrophy after knee arthroplasty and damage to the patella tendon insertion due to previous operations.

Surgical technique

A bone block 8?C10?cm long is excised with the tibial tubercle using an oscillating saw. A step cut inferior to the tibial plateau is created with a chisel. Refixation is performed with two cortical screws. Alternatively, in case of poor bone quality, refixation is accomplished with two cerclage wires.

Postoperative management

In case of stable refixation, full weight bearing is allowed with an extension brace for 2?C4?weeks and passive flexion is increased as tolerated. In case of poor bone quality, it is recommended that full weight bearing be postponed for 6?weeks, whereby full flexion is regained in 30° steps at 2, 4, and 6?weeks postoperatively.

Results

From 2001?C2004, 67 osteotomies of the tibial tubercle were performed for revision arthroplasty. During follow-up in 2010, no pseudarthrosis or dislocation was noticed. Postoperatively, two hematoma and one skin necrosis had to be revised. The risk of hematoma and pseudarthrosis or dislocation of the fragment can be minimized by using the correct operative technique.     

Revision total knee arthroplasty: Comparison of outcome following primary proximal tibial osteotomy or unicompartmental arthroplasty

Forty-three patients who had undergone revision total knee arthroplasty following either primary, medial unicondylar arthroplasty (23 patients) or valgus tibial osteotomy (20 patients) for medial compartment osteoarthritis were reviewed. Although the two groups had similar knee scores and range of motion at review, six patients (30%) who had undergone prior tibial osteotomy suffered serious postoperative complications. Of these, four patients had a deep infection. It was felt that several factors were responsible, resulting largely from difficulties in gaining access to the lateral tibial plateau and subsequently causing impairment of wound vascularity and healing. In contrast, those patients undergoing revision of unicondylar prostheses did not experience wound healing problems, but it was noted that in half of the cases, there was significant bone loss from the medial tibial plateau.     

A case of excision of peri-articular cyst and reattachment of meniscotibial ligament with suture anchor

The authors report a case of peri-articular cyst around the knee joint owing to insufficient meniscotibial ligament. After excision, the defective peripheries of the meniscus and capsule were securely re-attached to the margin of the tibial plateau using suture anchors. A 37-year-old man presented with right knee pain. Magnetic resonance imaging revealed a detached meniscotibial ligament (coronary ligament) on the anteromedial side of the knee joint and an elevated deep medial collateral ligament with cystic fluid collection. The cyst was excised by meticulous dissection to expose the free peripheral edge of the meniscus and the margin of the tibial plateau. Two suture anchors were placed immediately beneath the joint line under the subchondral bone. The attachment of the meniscus to the tibial plateau was rendered secure by arthroscopy. At 9 months postoperatively, the patients had no complaints related to the involved knee.     

髁限制性膝关节假体治疗严重膝内翻畸形合并胫骨平台内侧骨缺损

目的探讨髁限制性膝关节假体在膝骨关节炎严重内翻畸形合并胫骨平台内侧骨缺损行全膝关节置换术中的应用及疗效观察。方法回顾分析2008年1月至2011年1月12例骨性关节炎严重膝内翻畸形合并胫骨平台内侧骨缺损行髁限制性膝关节假体全膝关节置换术患者资料,术前负重位膝内翻畸形平均34°,胫骨平台内侧骨缺损为非包容性,依据AORI分型为Ⅱ、Ⅲ型,采用美国膝关节学会评分（knee society score,KSS）系统评估膝关节功能,包括膝评分和膝功能评分。结果本组均获随访,随访6～18个月,平均13个月,KSS膝评分和膝功能评分从术前（19.5±4.2）分、（16.2±5.4）分提高到术后（87.7±5.6）分、（85.4±8.3）分,分析术前及术后KSS膝评分及膝功能评分的差异有统计学意义。结论髁限制性膝关节假体全膝关节置换是治疗膝骨关节炎严重内翻畸形合并胫骨平台内侧骨缺损的有效方法,术中采取适度的软组织松解及正确的截骨,针对胫骨平台内侧骨缺损选用组合式金属垫块及假体延长柄,适度增加关节的限制性,可以转移力学负荷,增加假体的稳定性,最终获得良好效果。     

Resection specimen analysis of proximal tibial anatomy based on 100 total knee arthroplasty specimens

Although it is known that there is some asymmetry of the tibial plateau, most total knee arthroplasty designs currently have a symmetric tibial component. Using resection specimen analysis of the tibial plateau from 100 total knee arthroplasty specimens, the authors have examined the tibial plateau to further delineate, quantitatively, the medial and lateral tibial configuration. Unmagnified radiographs of each of the specimens were produced. A line was drawn along the mediolateral axis. The midpoint and points 10, 20, and 30% from the medial and lateral peripheries were then calculated. The average anteroposterior medial 10, 20, and 30% dimensions were 3.79, 4.74, and 5.06 cm, respectively. The average anteroposterior lateral 10, 20, and 30% dimensions were 3.48, 4.10, and 4.16 cm, respectively. The ratios of the lateral/medial anteroposterior distances at 10, 20, and 30% from the periphery were 92.10, 86.77, and 82.46%, respectively. A total knee arthroplasty system that recognizes the difference in the medial and lateral tibial plateaus and designs a prosthesis to account for the smaller, lateral tibial plateau may achieve the goal of maximizing tibial coverage as well as eliminate the problems associated with a symmetric design.     

Eine neuartige Knieendoprothese mit physiologischer Gelenkform

The natural tibiofemoral joint (TFJ) functions according to a roll-glide mechanism. In the stance phase (0–20° flexion), the femur rolls backwards over the tibia plateau, while further flexion causes increased gliding. This kinematics is based on the principle of a quadruple joint. The four morphological axes of rotation are the midpoints of the curvatures of the medial and lateral femoral condyles and the medial and lateral tibia plateau. In addition, the medial and lateral compartments are shifted a few millimetres in a sagittal direction, the medial tibia plateau being concave and the lateral plateau convex. In most knee arthroplasties, these factors are not taken into account; instead they are equipped with symmetrical medial and lateral joint surfaces. Thereby, the midpoints of the curvatures of the sagittal contours of the lateral and medial joint surfaces, on the femoral as well as on the tibial sides, create a common axis of rotation which does not allow a physiological roll-glide mechanism. The goal of this study was therefore to report on the biomechanical basis of the natural knee and to describe the development of a novel knee endoprosthesis based on a mathematical model. The design of the structurally new knee joint endoprosthesis has, on the lateral side, a convex shape of the tibial joint surface in a sagittal cross section. Furthermore, from a mathematical point of view, this knee endoprosthesis possesses essential kinematic and static properties similar to those of a physiological TFJ. Within the framework of the authorization tests, the endoprosthesis was examined according to ISO/WC 14243 in a knee simulator. The abrasion rates were, thereby, lower than or at least as good as those for conventional endoprostheses. The presented data demonstrate a novel concept in knee arthroplasty, which still has to be clinically confirmed by long term results.     

Oxford medial unicompartmental arthroplasty for focal spontaneous osteonecrosis of the knee

Background?Spontaneous osteonecrosis of the knee (SONK) is a distinct clinical condition occurring in patients without any associated risk factors. There is controversy as to the best method of treatment, and the available literature would suggest that patients with SONK have a worse outcome than those with primary osteoarthrosis when arthroplasty is performed.

We assessed the outcome of medial unicompartmental knee arthroplasty (UKA) using the Oxford prosthesis for end-stage focal spontaneous osteonecrosis of the knee (SONK; Ahlbäck grades III & IV).

Patients and methods?We assessed 29 knees (27 patients) with spontaneous osteonecrosis of the knee using the Oxford Knee Score. 26 knees had osteonecrosis of the medial femoral condyle and 3 had osteonecrosis of the medial tibial plateau. All had been operated on using the Oxford Medial Unicompartmental Knee Arthroplasty (UKA). This group was compared to a similar group (28 knees, 26 patients) who had undergone the same arthroplasty, but because of primary osteoarthrosis. Patients were matched for age, sex and time since operation. The mean length of follow-up was 5 (1–13) years.

Results?There were no implant failures in either group, but there was 1 death (from unrelated causes) 9 months after arthroplasty in the group with osteonecrosis. The mean Oxford Knee Score in the group with osteonecrosis was 38, and it was 40 in the group with osteoarthrosis.

Interpretation?Use of the Oxford Medial UKA for spontaneous focal osteonecrosis of the knee is reliable in the short to medium term, and gives results similar to those obtained when it is used for patients with primary osteoarthrosis.     

Osteonecrosis of the knee after arthroscopic surgery for meniscal tears and chondral lesions.

PURPOSE: Avascular necrosis of the knee following arthroscopic surgery has been described. The purpose of this article is to report a large series of patients who developed avascular necrosis after arthroscopy of the knee in an effort to delineate casual factors and results of treatment. TYPE OF STUDY: Case series. METHODS AND MATERIALS: The charts, radiographs, and magnetic resonance imaging (MRI) scans of patients who developed osteonecrosis (ON) of the knee after routine arthroscopic surgery were reviewed. Only those patients with no evidence of ON on preoperative MRI performed 6 weeks or longer after symptom onset and who postoperatively developed ON confirmed by repeat MRI and/or by pathological testing (specimens obtained at subsequent total knee arthroplasty) were included in the study. Seven patients with average age of 60 years (range, 41 to 79 years) met these inclusion criteria. RESULTS: The lesions noted at arthroscopy included 4 medial meniscus tears, 3 lateral meniscal tears, 6 chondromalacia of the medial femoral condyle, 2 chondromalacia of the medial tibial plateau, 1 chondromalacia of the lateral femoral condyle, 1 chondromalacia of the lateral tibial plateau, and 2 chondromalacia of the patella. The location of postarthroscopy ON correlated geographically with pre-existing pathology. All 7 patients had meniscal and/or chondral lesions addressed surgically in the compartment that subsequently developed ON. Six of the 7 patients had an adjacent ipsilateral meniscus tear treated with partial meniscectomy (4 medial, 2 lateral). In addition, of the 4 patients who developed ON of the medial femoral condyle, all had overlying chondromalacia, 3 of whom were treated with arthroscopic chondroplasty. Of the 2 patients with lateral meniscal tears, 1 developed ON of the lateral femoral condyle and the other developed ON of the lateral tibial plateau. Three patients went on to require total knee arthroplasty, and 2 high tibial osteotomy. One patient's ON resolved and another patient was lost to follow-up. CONCLUSION: ON should be considered in patients who have worsening symptoms after arthroscopy of the knee. These findings suggest a possible relationship between arthroscopic treatment of chondral and meniscal lesions and later appearance of ON in some patients. The role of arthroscopy in the development of ON needs to be further studied. Those at risk are elderly patients with chondral and meniscus lesions.     

Medial epicondyle osteotomy: a method of choice in severe varus knee arthroplasty

The purpose of this study was to evaluate the results of total knee arthroplasty (TKA) after using medial epicondyle osteotomy (MEO) as a balancing method for severe varus deformity and also to compare these results with those of TKA after using additional resection of the tibial medial plateau to correct this deformity. A total of 60 knees with severe varus deformity underwent TKA between 2006 and 2010. In 30 cases, we used MEO as a balancing method, and in other 30, additional medial tibial plateau resection was performed. The clinical outcomes were measured with the Knee Society score (KSS), the range of the motion and frontal laxity of the knee. The radiological outcomes were measured by anteroposterior simple radiographs to assess: the union state of the osteotomy site, the amount of resected tibial medial plateau bone and the femorotibial angle. The findings of the study show that in the MEO group the KSS improved from 21.13?±?13.6 to 92.1?±?7.6 points (P?<?0.001). Moreover, the range of motion increased from 70.3°?±?25.3° to 109.3°?±?12.7° (P?<?0.001). The femorotibial angle was corrected from a 22.6°?±?5.71° varus to a 4.0°?±?1.38° valgus (P?<?0.001) and frontal laxity decreased from 10.83°?±?3.9° to 0.33°?±?1.2° (P?<?0.001). No statistically significant differences were found between groups regarding the postoperative outcomes of KSS, range of motion, femorotibial angle and frontal laxity. The amount of resected tibial medial plateau bone was statistically significantly smaller in the MEO group (1.63?±?0.96?mm in the MEO group and 4.73?±?2.7?mm in the other group; P?<?0.001). In the MEO group, the mean thickness of the polyethylene insert was 12.66?±?1.21?mm, while in the second group, it was 13.73?±?1.59?mm, with statistically significant P?=?0.005. Fibrous union occurred in all knees in the MEO group. Using medial epicondyle osteotomy for varus knee when performing total knee arthroplasty could be a useful ligament-balancing technique to achieve medial stability of the knee. In addition, it could have considerable advantages towards the additional resection of the tibial medial plateau.