Spontaneous Osteonecrosis Of The Knee Research Articles

Analysis of medial unicompartmental knee arthroplasty for patients with spontaneous osteonecrosis of the knee

To analyse the effectiveness of unicompartmental knee arthroplasty (UKA) for the patients with spontaneous osteonecrosis of the knee (SONK). Between January 2012 and December 2016, 31 patients with SONK was admitted and treated with medial UKA. All patients were examined by both plain radiography and magnetic resonance images. The patients were composed of 5 men and 26 women with an average age of 64.3 years (range, 48-79 years), and with 16 left joints and 15 right joints. The average disease duration was 14.7 months (range, 6-26 months). Preoperative visual analogue scale (VAS) was 6.00±1.15, Hospital for Special Surgery (HSS) score was 55.77±11.03, and knee range of motion (ROM) was (114.68±10.40)°. The imaging examinations showed that all the lesions were located in the medial compartment of the knee joint and there were 19 patients with Aglietti stage Ⅳ and 12 patients with Aglietti stage Ⅴ. Preoperative femorotibial angle (FTA) was (177.39±1.63)° and posterior tibial slope (PTS) was (84.05±1.39)°. All the incisions healed by first intention. All patients were followed up 14-46 months (mean, 25 months). At last follow-up, VAS score was 2.06±0.72 and HSS score was 86.45±3.67, which both improved significantly when compared with preoperative scores ( t=22.73, P=0.00; t=-14.72, P=0.00). ROM was (118.06±3.80)° with no significant difference when compared with preoperative ROM ( t=-1.78, P=0.08). The X-ray films showed there was no severe adverse events, such as periprosthetic infection, aseptic loosening, bearing dislocation, and so on. At last follow- up, PTS was (85.30±1.19)° with significant difference compared with preoperative one ( t=-4.07, P=0.00); while FTA was (177.51±1.98)° with no significant difference when compared with preoperative FTA ( t=-0.38, P=0.71). UKA may be an optional management for SONK with minimally invasive, bone-preserving, and rapid recovery.

OSTEONECROSIS OF THE KNEE

Spontaneous osteonecrosis of the knee (SONK) is the most common type of knee osteonecrosis. It causes subchondral bone damage and in the majority of cases leads to cartilage damage and secondary osteoarthritis. The etiology is commonly explained with two main theories, vascular and traumatic. Vascular theory is based on disrupture of bone blood supply which causes local ischaemia and subchondral bone necrosis. Traumatic theory suggests the development of subchondral insufficiency fractures due to mechanical overload, which causes local oedema, ischaemia and necrosis. SONK typically appears in middle age and older women, with acute onset of sharp pain in the medial femoral condyle without predisposing trauma. Considering that the characteristic radiological signs are not seen on conventional radiography until advanced stage, magnetic resonance imaging is the gold standard in diagnostics. Treatment depends on the size and stage of the osteonecrotic lesion. Small osteonecrotic lesions are usually successfully treated non-operatively, which is based primarily on protected weight bearing and physical therapy. Medium osteonecrotic lesions are treated either non-operatively or operatively, while large osteonecrotic lesions are almost always treated operatively. Most commonly used joint preserving procedures include arthroscopic bone marrow stimulation using microfracture technique, core decompression, osteochondral autologous or homologous transplantation, artificial graft transplantation, and medial opening-wedge high tibial osteotomy. The treatment of choice after subchondral bone collapse is knee arthroplasty.

Clinical Characteristics and Treatment of Spontaneous Osteonecrosis of Medial Tibial Plateau: A Retrospective Case Study.

Background:In a small proportion of cases, spontaneous osteonecrosis of the knee (SONK) involves the medial tibial plateau (MT). Here, we introduced the clinical characteristics of spontaneous osteonecrosis of the MT and unicompartmental knee arthroplasty (UKA) as the favorable treatment for this situation based on a retrospective case study.Methods:Patients with spontaneous osteonecrosis of the MT, confirmed by magnetic resonance imaging (MRI) at Guangdong Provincial Hospital of Chinese Medicine (China) from March 2015 to June 2016, were included as a case serial and analyzed retrospectively. All patients underwent Oxford Medial UKA. The characteristics of their lesions, corresponding treatment, and results of follow-up were presented. The lesion scores and grade were determined according to the criteria of Ficat and Arlet.Results:In total, 22 patients (5 men, 17 women; mean age, 64.1 years) with spontaneous osteonecrosis of the MT were analyzed. The lesion stages assessment showed that 3 (14%) were Stage II, 10 (45%) were Stage III, 7 (32%) were Stage IV, and 2 (9%) were Stage V. In the sagittal plane, 7 (32%) were in the anterior region (MTa) and 15 (68%) were central (MTc). The lesion volume averaged 2.24 ± 0.79 cm3 (range: 1.57–3.08 cm3). Seventeen patients (77%) had Level III posterior medial meniscus root tears (MMRTs). All the patients underwent UKA. Average follow-up was 30.0 ± 6.4 months with a range of 23.0–38.0 months. The visual analog scale score was 7.78 ± 0.67 before surgery while decreased to 2.22 ± 1.09 at the final follow-up (P < 0.001). The Hospital for Special Surgery scores of pre-/post-surgery were 65.67 ± 5.45 and 84.10 ± 4.20, respectively (P < 0.001).Conclusions:SONK often occurs in the anterior and central tibial plateau due to abnormal stresses. Most of the patients had Level III posterior medial meniscus root tears. MRI is recommended for suspected cases to identify SONK at an early stage. The use of the Oxford Medial UKA for SONK of the MT is reliable both immediately and at follow-up.

A novel FAM20C mutation causing hypophosphatemic osteomalacia with osteosclerosis (mild Raine syndrome) in an elderly man with spontaneous osteonecrosis of the knee

Raine syndrome is characterized by FGF23-mediated hypophosphatemic osteomalacia with osteosclerosis caused by mutations in the FAM20C gene. We report a case of a 72-year-old man who presented with rapid progressive spontaneous osteonecrosis of the knee (SONK). A full osteologic assessment including dual energy X-ray absorptiometry (DXA), high-resolution peripheral quantitative computed tomography (HR-pQCT), and serum analyses revealed a high bone mass in the lumbar spine and hip (DXA T-score + 7.5 and + 4.7/+4.2) with increased bone microstructural parameters in the distal radius and tibia (BV/TV 127%, 140% of the age-matched mean, respectively), as well as a low bone turnover state. Phosphate levels were low due to renal phosphate wasting and high FGF23 levels (126.5pg/ml, reference range 23.2-95.4pg/ml). Using gene panel sequencing, we identified a novel FAM20C heterozygous missense mutation in combination with a homozygous duplication that potentially alters splicing. Taken together, this is the first case of mild Raine syndrome with spontaneous osteonecrosis of the knee, phosphate wasting, and a pronounced trabecular high bone mass phenotype.

Reliable patient-reported outcome measure and survivorship of UKA for primary spontaneous osteonecrosis.

Primary Spontaneous osteonecrosis of the knee (SPONK) was a result of a subchondral insufficiency fracture based on histopathological examinations. There were few studies examining patients who underwent unicompartmental knee arthroplasty (UKA) for the treatment of primary SPONK. The aim of this study was to investigate (1) patient-reported outcome measure (PROM), (2) survivorship of revision as end point and (3) survivorship of complication as end point in patients with primary SPONK. The clinical examinations of a consecutive series of 61 medial UKAs for primary SPONK of the medial femoral condyle from 2008 to 2012 were evaluated retrospectively at our institution. There were 18 males and 43 females with a mean age of 73.7years (60-91). In all patients, preoperative radiographs were analyzed according to the stage of primary SPONK. We conducted Kaplan-Meier survival analyses using revision and complications for any reasons as the end point. Mean follow-up was 6.6years (range 6-10). UKA using Physica ZUK (LIMA Corporate. UD, Italy) for SPONK improved patients' 2011 Knee Society symptom score, patient satisfaction, patient activities, EQ-5D and postoperative ranges of motion compared with their preoperative status (P < 0.01). Revision surgery was required in one knee (1.6%) due to postoperative fracture of the medial tibial plateau after a fall that occurred 6months postoperatively. The projected rate of survivorship of UKA was 90.4% at 10years (95% confidence interval 0.80-1). The projected rate of survivorship with complication at end point was 87.7% at 10years (95% confidence interval 0.76-0.99). The present study demonstrated that primary spontaneous osteonecrosis of the knee (SPONK) can be successfully be treated with UKA at a mean follow-up of 6.6years. II.

Effects of press-fit biphasic (collagen and HA/βTCP) scaffold with cell-based therapy on cartilage and subchondral bone repair knee defect in rabbits.

Human spontaneous osteonecrosis of the knee (SPONK) is still challenging as the current treatments do not allow the production of hyaline cartilage tissue. The aim of the present study was to explore the therapeutic potential of cartilage regeneration using a new biphasic scaffold (type I collagen/hydroxyapatite) previously loaded or not with concentrated bone marrow cells. Female rabbits were operated of one knee to create articular lesions of the trochlea (three holes of 4 × 4mm). The holes were left empty in the control group or were filled with the scaffold alone or the scaffold previously loaded with concentrated bone marrow cells. After twomonths, rabbits were sacrificed and the structure of the newly formed tissues were evaluated by macroscopic, MRI, and immunohistochemistry analyses. Macroscopic and MRI evaluation of the knees did not show differences between the three groups (p > 0.05). However, histological analysis demonstrated that a higher O'Driscoll score was obtained in the two groups treated with the scaffold, as compared to the control group (p < 0.05). The number of cells in treated area was higher in scaffold groups compared to the control group (p < 0.05). There was no difference for intensity of collagen type II between the groups (p > 0.05) but subchondral bone repair was significantly thicker in scaffold-treated groups than in the control group (1mm for the control group vs 2.1 and 2.6mm for scaffold groups). Furthermore, we observed that scaffolds previously loaded with concentrated bone marrow were more reabsorbed (p < 0.05). The use of a biphasic scaffold previously loaded with concentrated bone marrow significantly improves cartilage lesion healing.

A Rare Cause of Knee Pain in a Healthy Male Ultra-marathon Runner

HISTORY: A 58-year-old healthy male ultra-marathon runner presented with a 3-month history of atraumatic, gradually worsening right-sided anterior knee pain, aggravated by activity and associated with prominent morning stiffness and pain. Night pain was absent. Oral and parenteral NSAIDs provided no relief, nor did massaging. No history of smoking, alcohol or prior corticosteroid use was reported. PHYSICAL EXAMINATION: The R-knee was slightly swollen with no obvious deformities. No clinical intra-articular effusion was noted. Palpation revealed tenderness over the quadriceps tendon insertion and superomedial knee. In addition, the patient showed significant weakness of the right gluteus medius and quadriceps muscles. Tests for mechanical disruption and intra-articular injury were negative. Further examination of the hip and ankle joints as well as the general systemic examination were unremarkable. DIFFERENTIAL DIAGNOSIS: Quadriceps tendinopathy Patellar tendinopathy Patello-femoral pain syndrome Chondromalacia patellae Patellofemoral osteoarthritis Iliotibial band syndrome Other sources of knee pain (such as arthritis and gout) TEST AND RESULTS: Ultrasound: No soft tissue abnormalities. Suggestive area of a bony infarct in the distal femur. Plain radiographs (R-knee): Hypo-lucent area-distal femur (proximal to the condyles) MRI Knees: Bilateral areas of increased signal in the distal femoral shaft, suggestive of bilateral bony infarcts, were identified. Blood tests: within normal limits. FINAL WORKING DIAGNOSIS: Spontaneous osteonecrosis of the knee (SPONK)/ Ahlback`s Disease. TREATMENT AND OUTCOMES: 1. Initial management: Conservative - physical therapy and eccentric strengthening exercises. 2. Final outcome: Returned to physical activity, but it is still debated whether this athlete should return to full participation in ultra-marathon running.

Unicompartmental knee arthroplasty for spontaneous osteonecrosis of the knee: A meta-analysis.

Spontaneous osteonecrosis of the knee (SONK) is a poorly understood but debilitating disease entity. Total knee arthroplasty (TKA) is the standard of care for those patients who fail conservative management, but considering SONK's predilection for affecting a single knee compartment, unicompartmental knee arthroplasty (UKA) appears to be a more tailored option. Unfortunately, conflicting data exist on the utility of UKA in SONK. Thus, the purpose of this study was to evaluate functional outcomes and revision rates of UKA in the setting of SONK. A systematic literature search was performed to evaluate all studies examining patients who underwent UKA for SONK. Screening of the articles was performed using multiple Boolean search strings, methodological index for non-randomized studies criteria, and other selected exclusion criteria. Seven studies were included, with a total of 276 knees (273 patients). The mean age was 68 years (64-74 years), with a mean body mass index of 26 kg/m2 (25-29 kg/m2). The final range of motion was 125° (124-126°). Standardized mean difference (SMD) of clinical improvement pre- and post-outcome was 3.39 ( p < 0.001). The improvement in the visual analog score was 57.03 points, with an SMD of 4.57 ( p < 0.001). Revision rates were determined to be 5.51% (95% confidence interval of 1.96-10.69%). Our meta-analysis demonstrated that in properly selected patients, UKA could be an excellent alternative to TKA for patients with SONK. These data show that UKA has few complications, significant improvements on functional outcomes, and good survivorship at a mean follow-up of 6 years.

Medial joint line elevation of the tibia measured during surgery has a significant correlation with the limb alignment changes following medial unicompartmental knee arthroplasty.

This study aimed to determine the correlation between the change in joint line height calculated from the resected bone and insert thickness during surgery and the change in limb alignment following unicompartmental knee arthroplasty (UKA). It was hypothesized that joint line elevation is correlated with the change in limb alignment. A total of 74 consecutive patients diagnosed with either isolated medial compartmental osteoarthritis (38 patients) or spontaneous osteonecrosis of the knee (36 patients) were included. The thickness of the proximal tibial and distal femoral bony cuts was measured during surgery; using these values, the medial joint line elevation of the tibia (MJLET) and medial joint line reduction of the femur (MJLRF) were defined. The correlation between the amount of change in the hip-knee-ankle (HKA) angle before and after surgery (δHKA) and the thickness of the tibial insert (TI), MJLET, or MJLRF were evaluated. The mean values of δHKA, TI, MJLET, and MJLRF were 5.0° ± 2.6°, 8.5 ± 0.8, 4.4 ± 1.3, and 0.0 ± 1.1mm, respectively. The δHKA had a significant, but weak-positive correlation with the TI (P = 0.02), and moderate-positive correlation with MJLET (P < 0.001). However, no correlation was observed between δHKA and MJLRF. The MJLET measured during surgery had a significant moderate-positive correlation with the change in limb alignment following medial UKA. For clinical relevance, the surgeon can predict postoperative limb alignment after UKA by considering, intraoperatively, both the insert thickness and the depth of resection at the proximal tibia thus minimizing technical error to obtain an optimal alignment after UKA. Diagnostic study, level II.

Characteristics, management, and outcomes of spontaneous osteonecrosis of the knee in Indian population.

Spontaneous osteonecrosis of the knee affects the medial femoral condyle in patients above 55years of age. Many reports and studies are available from western countries. But there is a gross paucity of literature on spontaneous osteonecrosis of the knee (SPONK) in the Indian subcontinent, either it is under-reported or detected at a later stage. The aim of our study was to detect SPONK in Indian population and describe its characteristics, treatment, and outcome. A prospective study was conducted over a period of threeyears. All patients above 18years with knee pain at rest and medial condyle tenderness without joint laxity were evaluated with plain radiographs and MRI. Further tests were done if radiological signs of osteonecrosis were present. Various parameters were recoded like Visual Analog Scale (VAS), Knee Society Score (KSS), and MRI Osteoarthritis Knee Score. Conservative treatment consisted of a combination of NSAIDs and bisphosphonates. Decompression with bone grafting was done if there was no improvement or deterioration at threemonth follow-up. Ten patients were diagnosed with SPONK. The mean age was 50years with male predominance (60%) with the involvement of medial femoral condyle (80%) or left knee (70%). Most cases were in Koshino stage 1. Mean VAS was 6.5 and mean KSS was 59. All clinical parameters showed improvement at oneyear. A study with a bigger sample size and longer follow-up is needed to fill the lacunae of literature on this topic from the Indian subcontinent. In spite of the limitations, we did observe that in our population, males were more commonly affected than females, which is contrary to most studies on the subject. Also, the disease had an early age of onset (50years) in Indian population as compared to Western and East Asian populations. Combined therapy of NSAIDs and bisphosphonates shows excellent results over a period of oneyear. Joint-preserving surgeries are effective even in Koshino stage 3 SPONK.

The Role of Meniscal Tears in Spontaneous Osteonecrosis of the Knee: A Systematic Review of Suspected Etiology and a Call to Revisit Nomenclature

Background: The cause of spontaneous osteonecrosis of the knee (SONK) and postarthroscopic osteonecrosis of the knee is unknown, and the mechanisms involved have been poorly characterized. Hypothesis/Purpose: The purpose of this study was to perform a detailed systematic review of the literature to examine proposed etiological mechanisms for SONK in order to establish an improved understanding of the processes involved. We hypothesized that the etiology of SONK would be multifactorial. Study Design: Systematic review. Methods: A systematic review of the literature was performed by searching PubMed, Medline, Cochrane Database of Systematic Reviews, and the Cochrane Central Register of Controlled Trials. Inclusion criteria were all original research articles presented in the English language that reported on the suspected etiology of SONK. Reviews, case reports with fewer than 3 patients, cost-effectiveness studies, technical reports, editorial articles, surveys, special topics, letters to the editor, personal correspondence, and studies that only proposed factors for the progression of SONK were excluded. Results: After a comprehensive review of 255 articles, 26 articles were included for final analysis. Twenty-one (80.7%) of 26 articles implicated the role of the meniscus in the development of SONK, in an association with either meniscal tears or its development after meniscectomy. The medial meniscus and posterior meniscal root tears were implicated more frequently. All 4 studies incorporating histological findings supported the insufficiency fracture hypothesis as a pathological basis of SONK. Conclusion: Physicians should be cognizant of the high prevalence of medial meniscus root tears in patients with SONK. Meniscectomy and meniscal tears, particularly of the medial meniscus posterior root, increase contact pressures and create an environment from which insufficiency fractures can emanate. We believe the term SONK is a misrepresentation of the etiology and pathogenesis of the condition and should be replaced with subchondral insufficiency fractures of the knee. Further elucidation of the etiology is required.

Post-meniscectomy spontaneous osteonecrosis of the knee (SPONK): etiology, clinical presentation and treatment

Osteonecrosis of the knee is a disease that generates important limitations to the patient, but is still poorly understood. More recently, with the increasing number of arthroscopies, a new category of osteonecrosis was identified after meniscectomies. The purpose of this article is to review the concepts of the possible causes, clinical and radiological presentation of post-meniscectomy osteonecrosis.

Fresh Osteochondral Allograft Transplantation for Spontaneous Osteonecrosis of the Knee: A Case Series.

Background:Spontaneous osteonecrosis of the knee (SONK) is a clinical entity identified by acute knee pain usually associated with joint effusion, with radiographic findings of a radiolucent defect on the weightbearing area of the femoral condyle. Conservative treatment is initially undertaken; however, surgical procedures are often necessary. Historically, surgical options have included core decompression, cartilage repair, high tibial osteotomy, or joint arthroplasty. Few studies in the literature have reported the use of fresh osteochondral allograft (OCA) for the treatment of SONK lesions.Hypothesis:OCA transplantation is an effective treatment for SONK lesions on the medial femoral condyle.Study Design:Case series; Level of evidence, 4.Methods:A case series was analyzed of 7 patients treated with OCA for large SONK lesions of the medial femoral condyle with a minimum 4-year follow-up. All patients experienced failure of at least 6 months of conservative treatment and declined arthroplasty as the form of definitive treatment for medial femoral condyle lesion. All patients underwent OCA of the medial femoral condyle. Mean lesion size was 4.6 cm2 (range, 3.24-6.25 cm2), with a mean condylar width of 41.7 mm (range, 35.4-48.6 mm), resulting in a median proportion (lesion size/condylar width) of 56.8% (range, 32.7%-62.6%). The median surface allograft area was 5.1 cm2 (range, 3.2-6.3 cm2).Results:The median follow-up was 7.1 years (range, 4.5-14.1 years). No patient had additional surgery following OCA transplant; the allograft failure rate was 0%. Subjective outcome scores from the International Knee Documentation Committee, Knee injury and Osteoarthritis Outcome Score, and modified Merle d’Aubigné-Postel scale improved from preoperative assessment to the latest follow-up. All patients were extremely satisfied with the results of the OCA transplant.Conclusion:Fresh OCA transplantation demonstrated excellent efficacy, durability, and satisfaction in this group of patients with isolated stage 2 and 3 SONK lesions who had experienced failure of conservative treatment. Fresh osteochondral allografts are an attractive method for surgical management of selected patients with spontaneous osteonecrosis of the knee.

Arthrose, lésion méniscale dégénérative et ostéonécrose primitive du genou : une analyse simple de la marche améliore-t-elle la démarche diagnostique ?

IntroductionThe purpose of the current study was to compare the gait patterns in patients with three differing knee pathologies – knee osteoarthritis (OA), degenerative meniscal lesion (DML) and spontaneous osteonecrosis of the knee (SONK) and a group of healthy controls. HypothesisA simple gait test will detect differences between different knee pathologies. Material and methodsForty-seven patients with bilateral knee OA, 47 patients with DML, 28 patients with SONK and 27 healthy controls were included in this analysis. Patients underwent a spatiotemporal gait assessment and were asked to complete the Western Ontario and McMaster university (WOMAC) Index and the Short-Form (SF)-36 Health Survey. Anova tests, followed by Bonferroni multiple comparison tests and the Chi2 tests were performed for continuous and categorical variables, respectively. ResultsSignificant differences were found for all gait measures and clinical questionnaires between healthy controls and all knee conditions. Patients with SONK differed from patients with bilateral knee OA and DML in all gait measures and clinical questionnaires, except for WOMAC subscales. There were no significant differences between patients with bilateral knee OA and patients with DML. Symmetry was also examined and revealed asymmetry in some gait parameters in patients with SONK and DML. DiscussionBased on the differences in gait parameters that were found in the current study, adding an objective functional spatiotemporal gait test may assist in the diagnostic process of knee pathologies. Type of studyCase Control Study Level III.

Up to twelve year follow-up of the Oxford phase three unicompartmental knee replacement in China: seven hundred and eight knees from an independent centre.

There have been few large sample studies reporting the midterm outcome of Oxford phase 3 unicompartmental knee arthroplasty (UKA) in Asian patients. The study included 708 consecutive medial Oxford UKAs between February 2005 and May 2014 in Chinese patients. All cases were performed for the recommended indications with a minimally-invasive surgical technique. The functional and radiological outcomes were subsequently examined. In particular, we divided patients into the spontaneous osteonecrosis of the knee (SONK) group and the osteoarthritis (OA) group. All patients were reviewed with a mean follow-up of 6.2years (range 2.7-12years). At the latest follow up, the mean Oxford knee score (OKS) increased from 22.5 to 38.5 points, while the mean knee society score (KSS) increased from 43.6 to 86.1 points. The mean visual analogue scale pain score decreased from 7.9 to 1.5 points and the mean range of motion (ROM) increased from 112.5° to 125.2°. A total of 13 UKAs (1.88%) required revisions. The most common reason was bearing dislocation and osteoarthritis of the lateral compartment. Using revision for any cause as an endpoint, the five-year cumulative survival rate was 98.8% and the ten-year survival rate was 94.3%. There was no statistically significant difference between the SONK group and the OA group for the five-year cumulative survival rate (98.7% vs. 98.8%, P>0.05). This study demonstrates that Oxford UKA is a good option for the treatment of anteromedial OA and SONK of the knee in Asian patients.

Association between medial meniscus extrusion and spontaneous osteonecrosis of the knee.

Medial meniscus tear has been proposed as a potential etiology of spontaneous osteonecrosis of the knee (SONK). Disruption of collagen fibers within the meniscus causes meniscal extrusion, which results in alteration in load distribution in the knee. Our purpose was to determine whether the extent of medial meniscus extrusion correlates with the severity of SONK in the medial femoral condyle. Radiological stage of SONK and femorotibial angle (FTA) were determined on knee radiographs. Ellipsoid volume of SONK lesion and meniscal pathology (degeneration, tear and extrusion) were evaluated by magnetic resonance imaging. All the 18 knees with SONK in the present study showed substantial extrusion (≥ 3 mm) and degeneration of the medial meniscus. The extent of meniscal extrusion and FTA were strongly associated with the stage and volume of the SONK lesion. Multiple linear regression analysis revealed that medial meniscus extrusion and FTA were useful predictors of the volume of the SONK lesion. There was high association of medial meniscus extrusion and FTA with the radiological stage and volume of the SONK lesion. Increased loading in the medial femoral condyle with greater extrusion of medial meniscus and varus alignment may contribute to expansion and secondary osteoarthritic changes of a SONK lesion.

Knee osteoarthritis, degenerative meniscal lesion and osteonecrosis of the knee: Can a simple gait test direct us to a better clinical diagnosis

IntroductionThe purpose of the current study was to compare the gait patterns in patients with three differing knee pathologies – knee osteoarthritis (OA), degenerative meniscal lesion (DML) and spontaneous osteonecrosis of the knee (SONK) and a group of healthy controls. HypothesisA simple gait test will detect differences between different knee pathologies. Material and methodsForty-seven patients with bilateral knee OA, 47 patients with DML, 28 patients with SONK and 27 healthy controls were included in this analysis. Patients underwent a spatiotemporal gait assessment and were asked to complete the Western Ontario and McMaster University (WOMAC) Index and the Short-Form (SF)-36 Health Survey. ANOVA tests, followed by Bonferroni multiple comparison tests and the Chi2 tests were performed for continuous and categorical variables, respectively. ResultsSignificant differences were found for all gait measures and clinical questionnaires between healthy controls and all knee conditions. Patients with SONK differed from patients with bilateral knee OA and DML in all gait measures and clinical questionnaires, except for WOMAC subscales. There were no significant differences between patients with bilateral knee OA and patients with DML. Symmetry was also examined and revealed asymmetry in some gait parameters in patients with SONK and DML. DiscussionBased on the differences in gait parameters that were found in the current study, adding an objective functional spatiotemporal gait test may assist in the diagnostic process of knee pathologies. Type of studyCase Control study Level III.

The role of medial meniscus posterior root tear and proximal tibial morphology in the development of spontaneous osteonecrosis and osteoarthritis of the knee

BackgroundMedial meniscus posterior root tear (MMPRT) has been reported to play a key role in the development of spontaneous osteonecrosis of the knee (SONK) and osteoarthritis (OA) of the knee. However, little is known about the differences in the development of SONK and OA after MMPRT. The purpose of this study was to investigate the factors contributing to the development of these conditions. MethodsWe evaluated the existence of MMPRT and the extent of medial meniscal extrusion in preoperative magnetic resonance images and proximal tibial morphology in radiographs of 45 patients with SONK and 104 patients with OA who underwent knee surgery. ResultsThere were no significant differences in age, gender, height, weight, and body mass index between the two groups. The incidence of MMPRT and the mean posterior tibial slope (PTS) were significantly higher in SONK than in OA patients (62.2% versus 34.3%, P=0.002, and 12.8° versus 10.5°, P<0.001, respectively). The mean extent of meniscal extrusion was larger in OA than in SONK patients (7.5mm versus 5.3mm, P<0.001). The mean tibial varus angle was 4.8° in SONK and 5.4° in OA, with no significant difference between the two (P=0.088). Multivariable logistic regression analysis showed that compared with OA, SONK was more closely associated with the existence of MMPRT and had a smaller extent of medial meniscus extrusion and higher PTS. ConclusionMMRPT and higher PTS were more closely associated with the development of SONK than with that of OA.

Spontaneous Osteonecrosis of the Knee: A Retrospective Analysis by Using MRI and DEXA.

Objective: Although there are many etiology and prediction for prognosis of spontaneous osteonecrosis of the knee (SONK) by using radiological examinations, these issue have not been clarified yet. Furthermore, most of the studies evaluated them by only radiological examination such as magnetic resonance imaging (MRI), bone mineral density (BMD) in dual-energy X-ray abosorptiometry (DEXA) or plain X-ray. Therefore, we focused our investigation on the measurements of the affected área in MRI and BMD in DEXA, and whether these results were conected with the cause and prognosis of SONK or not.Method:A consecutive case series of two groups composed of ten osteoporotic patients who were suffering from SONK was considered. Based on the severity or duration of pain, one group was treated with surgical procedure which was unicompartmental knee arthroplasty (UKA), the other received conservative treatment. Both groups underwent DEXA in their distal fêmur and próximal tíbia and all patients who took MRI measured the affected lesion in low and high intensity área on T2 weighted images. This data was analyzed from these areas and units.Results:Significant decrease in regional boné density of the affected femoral condyle compared to the unaffected side was observed. However, the boné mineral density in the affected side was similar in the non-operative and surgical group. The área of the lesion which showed in both low and high intensity indicated that the operation group was significantly larger than the conservative group on T2 weighted images.Conclusion:The cause and prognosis of SONK have a close relationship with the size of the affected lesion and decreased boné mineral density

Osteochondral autograft transfer (OAT) combined with OWHTO for spontaneous osteonecrosis of the knee (SONK)

Osteochondral autograft transfer (OAT) combined with OWHTO for spontaneous osteonecrosis of the knee (SONK)