Biomechanical evaluation of three patellar fixation techniques for MPFL reconstruction: Load to failure did not differ but interference screw stabilization was stiffer than suture anchor and suture-knot fixation.

PURPOSE: The purpose of this study was to compare the maximum load to failure and stiffness of three medial patella-femoral ligament (MPFL) reconstruction techniques: (i) suture anchor fixation (SA), (ii) interference screw fixation (SF), and (iii) suture knot (SK) patellar fixation. The null hypothesis was that the comparison between these three different patella fixation techniques would show no difference in the ultimate failure load and stiffness. METHODS: Reconstruction of the MPFL with gracilis tendon autograft was performed in 12 pairs of fresh-frozen cadaveric knees (24 knees total; mean age, 63.6 [Formula: see text] 8.0 years). The specimens were randomly distributed into 3 groups of 8 specimens; SA reconstruction was completed with two 3.0-mm metal suture anchors; (SF) fixation was accomplished by two 6-mm bio-composite interference screws; SK fixation at the lateral side of the patella was accomplished after drilling two semi-patellar tunnels with a diameter of 4.5 mm. The reconstructions were subjected to cyclic loading for 10 cycles to 30 N and tested to failure at a constant displacement rate of 15 mm/min using a materials-testing machine (MTS 810 Universal Testing System). The final load of failure (N), stiffness (N / mm) and failure mode was recorded in each specimen and followed by statistical analysis. RESULTS: There was no significant difference in mean ultimate failure load among the three groups. The SK group failed at a mean ([Formula: see text] SD) ultimate load of 253.5 [Formula: see text] 38.2 N, the SA group failed at 243 [Formula: see text] 41.9 N and the SF group at 263.2 [Formula: see text] 9.06 N. The SF group had a mean stiffness of 37.8 [Formula: see text] 5.7 N/mm. This was significantly higher (p < 0.05) than the mean stiffness value achieved for the SK group 21.4 [Formula: see text] 9.5 N/mm and the SA group 18.7 [Formula: see text] 3.4 N/mm. The most common mode of failure in the SA group was anchor pullout, and in the SK group was failure at the graft-suture interface. All the reconstructions in the SF group failed due to tendon graft slippage from the tunnel. CONCLUSION: Load to failure was not significantly different between the 3 techniques. However, screw fixation was found to be significantly stronger than the anchor and the suture knot fixation in terms of rigidity of the reconstruction. From a clinical point of view, all methods of fixation can be used reliably for MPFL reconstruction, since they were found to be stronger than the native MPFL.

Synovial plicae of the knee joint: the role of advanced MRI.

Synovial plicae are normal anatomical structures of the knee that may become symptomatic. MRI is an established technique for evaluating the anatomy of the knee, and it is a valuable tool for detecting plicae because of its high resolution resulting in increased tissue characterisation. At MRI, knee plicae appear as low-signal-intensity structures of variable size and thickness, and they are better visualised at fluid-sensitive sequences with or without fat suppression. The combined use of clinical examination and MRI may also facilitate the diagnosis of fibrotic or inflamed plicae that may be symptomatic. Arthroscopy remains the gold standard for recognition and repair of knee plicae in cases of knee dysfunction.

Case report: Mesenchymal chondrosarcoma of the lumbar spine in a child.

BACKGROUND: Chondrosarcomas of the spine constitute 4% to 10% of all primary spinal bone tumors and approximately 70% of the cases occur during the second or third decade of life. Mesenchymal chondrosarcoma is a rare aggressive variant of chondrosarcoma. The prognosis of mesenchymal chondrosarcoma is usually poor with a tendency for late local recurrence and metastasis. CASE DESCRIPTION: We describe a case of primary mesenchymal chondrosarcoma affecting the L5 vertebra of a 9-year-old girl. The patient underwent a staged circumferential resection of the tumor after three rounds of neoadjuvant chemotherapy. The patient had additional chemotherapy and radiation therapy as an intralesional margin was achieved during the procedure. At 9 years followup, the patient was asymptomatic, neurologically intact, and remained in remission. LITERATURE REVIEW: We identified only four previously published cases of spinal mesenchymal chondrosarcoma in childhood, two of which had relatively early recurrence and poor survival, and two survived but with only short followup. PURPOSES AND CLINICAL RELEVANCE: As the clinical and radiographic findings of mesenchymal chondrosarcoma are nonspecific, the diagnosis of this rare tumor requires careful histopathologic review of the specimens. We suggest the differential diagnosis of every primary intraspinal tumor include tumors of mesenchymal origin. The prognosis is apparently not uniformly poor.

Arthroscopic Single-Row Versus Double-Row Suture Bridge Technique for Rotator Cuff Tears in Patients Younger Than 55 Years: A Prospective Comparative Study.

BACKGROUND: When arthroscopic rotator cuff repair is performed on a young patient, long-lasting structural and functional tendon integrity is desired. A fixation technique that potentially provides superior tendon healing should be considered for the younger population to achieve long-term clinical success. Hypothesis/Purpose: The purpose was to compare the radiological and clinical midterm results between single-row and double-row (ie, suture bridge) fixation techniques for arthroscopic rotator cuff repair in patients younger than 55 years. We hypothesized that a double-row technique would lead to improved tendon healing, resulting in superior mid- to long-term clinical outcomes. STUDY DESIGN: Cohort study; Level of evidence, 2. METHODS: A consecutive series of 66 patients younger than 55 years with a medium to large full-thickness tear of supraspinatus and infraspinatus tendons who underwent arthroscopic single-row or double-row (ie, suture bridge) repair were enrolled and prospectively observed. Thirty-four and 32 patients were assigned to single-row and double-row groups, respectively. Postoperatively, tendon integrity was assessed by MRI following Sugaya's classification at a minimum of 12 months, and clinical outcomes were assessed with the Constant score and the University of California, Los Angeles (UCLA) score at a minimum of 2 years. RESULTS: Mean follow-up time was 46 months (range, 28-50 months). A higher tendon healing rate was obtained in the double-row group compared with the single-row group (84% and 61%, respectively [ P < .05]). Although no difference in outcome scores was observed between the 2 techniques, patients with healed tendon demonstrated superior clinical outcomes compared with patients who had retorn tendon (UCLA score, 34.2 and 27.6, respectively [ P < .05]; Constant score, 94 and 76, respectively [ P < .05]). CONCLUSION: The double-row repair technique potentially provides superior tendon healing compared with the single-row technique. Double-row repair should be considered for patients younger than 55 years with medium to large rotator cuff tears.

Paraoxonase 1 gene polymorphisms in patients with osteonecrosis of the femoral head with and without cerebral white matter lesions.

Cerebral white matter lesions (WML) are present in more than 50% of patients with osteonecrosis of the femoral head (ONFH). Paraoxonase 1 (PON1) gene product is a detoxifying and pesticide metabolizing enzyme. Genetic variants of the PON1 gene have been found to influence the occurrence and progression of WML. We examined whether two PON1 polymorphisms (M55L and R192Q) are associated with ONFH and influence the occurrence of WML. We studied 104 patients with ONFH and 113 healthy age- and sex-matched subjects. We used logistic regression models to examine associations and survival analyses (Cox proportional hazards models) to examine possible influence of alleles on age at onset of ONFH. We found no association of PON1 M55L alleles and genotypes with ONFH. The distribution of PON1 Q192R alleles (p = 0.001) and genotypes (QQ vs. QR/RR) (p = 0.004) were statistically different between controls and patients. Patients with QQ genotype had six times higher risk for WML at brain MRI (adjusted OR 5.95; 95% CI 1.30-27.03; p = 0.02). In Cox models, there was a significant association of allele Q with risk for ONFH indicating a possible dose effect (HR = 1.43; 95%CI = 1.04-1.97; p for trend = 0.03). We conclude that individuals with PON1 192QQ genotype may have increased risk for ONFH and WMLeOn.

The role of MR imaging in staging femoral head osteonecrosis.

Reliability, accuracy and prognostic value of any classification system are important in evaluation and treatment of femoral head osteonecrosis. The purpose of the present study was to correlate the plain radiographs with MRI in femoral head osteonecrosis. Between 2000 and 2005, 115 hips (72 patients) were evaluated and classified according to the ARCO classification criteria with the use of plain radiographs and additional application of MRI. Classification was performed by consensus between a musculoskeletal radiologist and an orthopaedic surgeon. Sensitivity (SEN), specificity (SP), positive (PPV) and negative (NPV) predictive value of X-rays were estimated. According to MRI, 17 hips were classified as stage I, 25 as stage II, 48 as stage III and 25 as stage IV. The SEN, SP, PPV and NPV of plain radiographs were for stage II 88%, 90.5%, 78.6% and 95%; for stage III 79.2% 82%, 80.8% and 87.2%; for stage IV 76%, 100%, 100% and 90.9%, respectively. The agreement between plain radiographs and MRI was 80.6% for staging the disease, 71.2% for recording the location of the osteonecrotic lesion, 67.1% for evaluating the size of the lesion, 79.2% for the presence of collapse of the articular surface and 56.3% for the degree of collapse. In conclusion, the ARCO classification could miss important information in stages II and III, where treatment aims at preservation of the hip joint integrity. The results of the present study suggest that MRI should be incorporated in the classification of osteonecrosis (stages II and III), to add accuracy and prognostic value.

Fast sequences MR imaging at the investigation of painful skeletal sites in patients with hip osteonecrosis.

BACKGROUND: Multiple osteonecrotic foci can be clinically silent when located in metaphyses and becomes painful when it affects juxta-articular areas. The purpose of this study was to assess the value of fast MR imaging to depict the underlying pathology in cases with skeletal pain other than the already diagnosed hip osteonecrosis. METHODS/DESIGN: Between 2008 and 2013, 49 patients with already diagnosed hip osteonecrosis reported symptoms of deep skeletal pain in an anatomical site different from the affected hip joint. All patients after thorough history & clinical examination underwent evaluation with x-rays and a single fat suppressed sequence with MR Imaging applying either T2-w TSE or STIR-TSE at the painful site. False positive and false negative findings were recorded for the conventional x-rays and compared to MRI. DISCUSSION: Forty four (89.8%) patients were positive for osteonecrotic lesions in this study and 76 symptomatic osteonecrosis lesions were revealed at 14 distinct anatomic sites. The agreement between the x-ray findings and the MR imaging regarding osteonecrosis was 46.9%. Plain x-rays showed 43.4% sensitivity, 100% specificity, 100% positive predictive value and 10.4% negative predictive value. Fast MR imaging with fat suppressed sequences is necessary and adequate as a single method for the investigation of painful skeletal sites in patients with already diagnosed hip osteonecrosis. It allows early diagnosis of the potentially debilitating multiple juxta-articular lesions and consequently their prompt management.

MR imaging findings in early osteoarthritis of the knee.

PURPOSE: To carry out a modern diagnostic survey among patients with a clinical and radiological diagnosis of early osteoarthritis of the knee. MATERIALS AND METHODS: A magnetic resonance imaging survey was performed on 70 patients (82 knees) with a mean age of 59 years. (range, 40-71 years) who had chronic knee pain, clinical diagnosis of early osteoarthritis of the knee and conventional knee radiographs classified as 1 and 2 on the Kellgren-Lawrence scale. RESULTS: A variety of different disorders was found; degenerative meniscal lesions with or without ruptures of the anterior cruciate ligament in 70.7% of the knees, osteonecrosis of the femoral and tibial condyles in 9.75%, osteophytes and degenerative articular cartilage lesions in 8.54%, transient osteoporosis in 2.44% and benign neoplasms and cysts in 6.1%. CONCLUSIONS: The existence of such a heterogenous group of disorders in these "early osteoarthritic knees" may explain failures in treatment and it may justify a modern MRI imaging approach to proper diagnosis.

Increased frequency of white matter lesions in patients with osteonecrosis (WMLeOn) of the femoral head.

White matter lesions (WML) are commonly seen in cerebral MR imaging in normal and demented elderly people or young people suffering from migraine. We present data showing that WML are detected in an unexpectedly high frequency (56.9%) in patients with non-traumatic osteonecrosis of the femoral head compared to age and sex-matched controls. We designated the coexistence of WML and osteonecrosis as white matter lesions in osteonecrosis (WMLeON). We examined the possible association of WMLeON with hyperlipidaemia and other risk factors for WML or osteonecrosis of the femoral head. The frequency of history of corticosteroid treatment was statistically lower in patients with WMLeON (58.6%) compared to those without it (90.1%) (P = 0.03). We found no association of WMLeON with diabetes, stroke, hyperlipidaemia, migraine, smoking, alcohol consumption, hypertension, atrial fibrillation, or systemic lupus erythematosus. Although, the clinical significance of WMLeON is still unknown, this finding supports, at least, the hypothesis that non-traumatic osteonecrosis is indeed a multisystem disorder rather than a disease of human skeleton.

Evaluation of meniscal repair with serial magnetic resonance imaging: a comparative study between conventional MRI and indirect MR arthrography.

OBJECTIVE: To prospectively investigate the healing process of meniscal repair with plain magnetic resonance imaging (MRI) and indirect MR arthrography and to compare the two methods. MATERIALS AND METHODS: Twenty patients with an arthroscopic meniscal repair without clinical symptoms underwent conventional and indirect MR arthrography of the affected knee, 3, 6 and 12 months after the index operation applying a T1-w Spin Echo sequence in three planes. The size of the tear gap was measured on transverse images. The signal-to-noise ratio and the configuration of the abnormal signal were evaluated in the coronal images. RESULTS: All patients demonstrated abnormal signal intensity at the side of the meniscal repair. The size of the gap at the previous tear side, reduced significantly by 45 and 40% on conventional MRI and indirect MR arthrography respectively, from 3 months to 1 year (P < 0.05). The signal-to-noise ratio of the intrameniscal abnormal signal reduced significantly and approximately 50% from 3 to 6 months, and from 6 to 12 months postoperatively, as demonstrated with indirect MR arthrography. However, as opposed to normal meniscus, the signal-to-noise ratio of the abnormal area remains 5.5 times higher 12 months postoperatively. In contrast, the reduction of signal-to-noise ratio of the abnormal area at conventional MRI was not significant even from 3 to 12 months. In 90% of the cases, the indirect MR arthrography showed the intrameniscal abnormal signal on plain MRI, to extend to the articular surface as opposed to 25% on plain MRI. CONCLUSION: With indirect MR arthrography, the natural process of meniscal healing can be evaluated. Significant reduction of the size of the tear gap and significant reduction of the signal-to-noise ratio of the abnormal signal as well as its configuration are the main parameters interpretating the normal healing process.

MR imaging findings in transient osteoporosis of the hip.

PURPOSE: The authors sought to describe the magnetic resonance (MR) imaging findings including perfusion imaging, in association with the course of acute bone marrow oedema syndrome (aBMEs), in a group of patients with acute hip pain and a final diagnosis of transient osteoporosis of the hip (TOH). MATERIALS AND METHODS: From 217 patients referred with a probable diagnosis of avascular necrosis (AVN) of the femoral head, we identified 42 patients who had clinical and radiographic findings not relevant to AVN. MR imaging examinations were performed on a 1.0T scanner. Perfusion imaging was performed in 20 patients. The bone marrow oedema (BME) was classified in four stages. In addition, the presence or absence of oedema in the subchondral area and the presence of other subchondral lesions were recorded. Acetabular bone marrow was also assessed for the presence of oedema. The quantitative measurements included: maximum size of the effusion, percentage of enhancement (PE) and time of peak enhancement of abnormal marrow compared to the first pass, on the perfusion images. RESULTS: Osteopenia was present on plain radiographs in 87% of cases. The most common pattern of BME was extending to the femoral head and neck. Acetabulum was involved in 16.6%. In 22.6% the BME spared the subchondral region of the femoral head. There were two cases (4.7%) with subchondral changes. A joint effusion was noted in 33 of the 42 patients. On perfusion imaging, a delayed peak enhancement was noted in 20 patients between 40 and 65 s after the first pass of contrast. No patient had any evidence of femoral head collapse or change in sphericity on follow-up MRI. None of the patients developed avascular necrosis in a time frame of 18 months from the onset of the acute hip pain. CONCLUSION: The aBMEs MR imaging pattern varies and is most commonly appearing on X-rays as osteopenia. Absence of subcondral lesions, delayed peak enhancement of the abnormal marrow on perfusion images, and sparing of subchondral zone from marrow oedema are MR imaging findings highly correlated to TOH.

Fat-suppressed 3D-T1-weighted-echo planar imaging: comparison with fat-suppressed 3D-T1-weighted-gradient echo in imaging the cartilage of the knee.

This study was conducted to compare a three-dimensional (3D) multi-shot echo-planar imaging (EPI) sequence with fat-suppression (FS) with the 3D-fat-suppressed gradient echo (GRE-FS) sequence in imaging the cartilage of the knee. One hundred sixty-nine patients were studied prospectively. The cartilage was imaged in the sagittal plane with: (a) 3D-T1-EPI-FS and (b) 3D-T1-GRE-FS sequences using a 1T MR scanner. The signal-to-noise ratio (SNR) of bone (b) and cartilage (c), and relative contrast (ReCon) between bone and cartilage and meniscus and cartilage were measured in 60 patients with arthroscopically normal cartilage. The imaging accuracy was assessed by comparing with linear regression analysis (length and depth) 32 defects in the cartilage of cadaveric (human and bovine) knees. The 3D-T1-EPI-FS provided better bone marrow signal suppression, better SNRc and better ReCon(bc) and ReCon(cm) (p<0.01). The 3D-T1-EPI-FS showed better accuracy concerning the depth of the defects and the 3D-T1-GRE-FS better accuracy concerning the length of the defects. In conclusion, the 3D-T1-EPI-FS pulse sequence could be included in the routine protocol in imaging the cartilage of the knee because it achieves high SNR of the cartilage and high ReCon compared to the surrounding structures, at a reduced scan time.

Psychological distress, personality traits and functional disability in patients with osteonecrosis of the femoral head.

BACKGROUND: The aim of the present study was to investigate personality traits, psychological distress and functional disability in patients with non-traumatic osteonecrosis of the femoral head (ONFH). METHODS: Sixty-seven patients participated in the study, 48 males and 19 females. The mean age was 37.6 years (SD: 10.92, range: 15 - 61). Seventy-five healthy individuals, age and sex matched, served as controls. Socio-demographic information and clinical data were collected. The following instruments were used: the General Health Questionnaire (GHQ-28), the Defence Style Questionnaire (DSQ) and the World Health Organization Disability Assessment Schedule II (WHO-DAS II). RESULTS: Patients suffering from ONFH presented higher scores at the GHQ-28 compared to healthy controls (P < 0.001). Duration of disease (P < 0.047) and age (P < 0.023) were the main factors associated with psychological distress (P < 0.003). Personality traits such as image distorting (P < 0.025) and self-sacrificing (P < 0.029) were identified in patients with ONFH compared to healthy controls. Functional disability was associated with high scores at GHQ-28 scale (P < 0.001). The "adaptive personality structure", as measured by DSQ was negatively associated with functional impairment (P < 0.022). CONCLUSIONS: Patients with ONFH more commonly present symptoms of psychological distress associated with distinct functional clinical parameters. The present study also reveals the role of personality traits. Further investigation could specify the possible influence of psychopathology and personality traits or coping strategies on the course of disease.

Munchausen syndrome: A differential diagnostic trap for hand surgeons.

A 24-year-old woman was referred with an extremely painful, stiff, swollen, and hypersensitive right upper extremity. She had history of four previous operations on the same extremity. The primary diagnosis was complex regional pain syndrome. During the next few days her symptoms worsened and she developed fever. It was discovered that the patient was preheating more than one thermometer and was intentionally injuring herself. The final diagnosis was Munchausen syndrome.

Localized pigmented villonodular synovitis in the anteromedial compartment of the knee associated with cartilage lesions of the medial femoral condyle: report of a case and review of the literature.

Localized pigmented villonodular synovitis (PVNS) of the knee is an uncommon entity, presenting with different clinical signs and symptoms. We report on a case of a 42-year-old woman who presented with a 3-year history of knee pain and mechanical problems such as locking. On examination she was found to have a palpable and painful mass over the anteromedial joint line. Magnetic resonance imaging (MRI) revealed a soft tissue mass in the anteromedial compartment of the knee joint. The lesion was completely resected arthroscopically, and histologic examination confirmed the diagnosis of localized PVNS. The patient was free of symptoms, and MRI examination showed no evidence of recurrence at 1-year follow-up.