Anterior glenoid perforation with suture anchor causing subscapularis irritation and pain.

BACKGROUND: Suture anchors for labral repair have been associated with complications including suprascapular notch encroachment and osteolysis. CASE DESCRIPTION: We present a case of suture anchor penetration of the anterior glenoid neck leading to pain secondary to subscapularis muscle irritation in a 14-year-old boy. The patient had labral repair and subsequent anterior shoulder pain which resolved after anchor removal. LITERATURE REVIEW: Chondrolysis of the glenohumeral joint has been described following labral repair with knotless anchors. There have also been cases of injury to the suprascapular nerve following labral repair. However, we are not aware of any reports describing suture anchor penetration of the anterior glenoid neck leading to pain secondary to subscapularis muscle irritation. PURPOSES AND CLINICAL RELEVANCE: Labral repair has become a common and routine procedure, but complications can occur. We report a new complication related to osseous penetration of the anterior glenoid neck of the scapula by a suture anchor. We identified the complication using magnetic resonance imaging, an important part in reproducible, noninvasive, and objective assessment of the postoperative shoulder. We also present the technique for anchor removal used to resolve the patient's anterior shoulder pain.

Evaluation of a porous polyurethane scaffold in a partial meniscal defect ovine model.

PURPOSE: The objective of this study was to assess the performance of a degradable porous polyurethane scaffold in a partial meniscectomy ovine model. METHODS: We subjected 42 skeletally mature ewes to unilateral partial excision of the lateral meniscus. In 19 animals the defect was left unfilled; in 23 animals a scaffold was inserted. Knees were examined by magnetic resonance imaging, gross inspection, and histologic inspection of the cartilage of the tibial plateau. RESULTS: In contrast to what has been previously reported in a complete meniscal replacement model, cartilage damage did not occur under the site of scaffold implantation; this was likely influenced by the rapid infiltration of cells and the dense tissue that formed within the scaffold. Cartilage damage in both groups was located close to the midline of the joint. No significant difference in the condition of the articular cartilage of the tibial plateau was seen between groups up to 12 months postoperatively. This result was influenced by the fact that the partly meniscectomized knees also showed unexpected tissue regeneration within the defect site, which raises concern about the suitability of using a partial meniscectomy as a control in the ovine model. CONCLUSIONS: Our study has shown that implantation of a polyurethane scaffold in a partial meniscectomy ovine model promotes tissue ingrowth without damaging the cartilage with which it articulates. CLINICAL RELEVANCE: Meniscal deficiency is a common occurrence, the effective clinical management of which is limited by the absence of an off-the-shelf implantable construct.

Concentrated bone marrow aspirate improves full-thickness cartilage repair compared with microfracture in the equine model.

BACKGROUND: The purpose of this study was to compare the outcomes of treatment with bone marrow aspirate concentrate, a simple, one-step, autogenous, and arthroscopically applicable method, with the outcomes of microfracture with regard to the repair of full-thickness cartilage defects in an equine model. METHODS: Extensive (15-mm-diameter) full-thickness cartilage defects were created on the lateral trochlear ridge of the femur in twelve horses. Bone marrow was aspirated from the sternum and centrifuged to generate the bone marrow concentrate. The defects were treated with bone marrow concentrate and microfracture or with microfracture alone. Second-look arthroscopy was performed at three months, and the horses were killed at eight months. Repair was assessed with use of macroscopic and histological scoring systems as well as with quantitative magnetic resonance imaging. RESULTS: No adverse reactions due to the microfracture or the bone marrow concentrate were observed. At eight months, macroscopic scores (mean and standard error of the mean, 9.4 + or - 1.2 compared with 4.4 + or - 1.2; p = 0.009) and histological scores (11.1 + or - 1.6 compared with 6.4 + or - 1.2; p = 0.02) indicated improvement in the repair tissue in the bone marrow concentrate group compared with that in the microfracture group. All scoring systems and magnetic resonance imaging data indicated that delivery of the bone marrow concentrate resulted in increased fill of the defects and improved integration of repair tissue into surrounding normal cartilage. In addition, there was greater type-II collagen content and improved orientation of the collagen as well as significantly more glycosaminoglycan in the bone marrow concentrate-treated defects than in the microfracture-treated defects. CONCLUSIONS: Delivery of bone marrow concentrate can result in healing of acute full-thickness cartilage defects that is superior to that after microfracture alone in an equine model. CLINICAL RELEVANCE: Delivery of bone marrow concentrate to cartilage defects has the clinical potential to improve cartilage healing, providing a simple, cost-effective, arthroscopically applicable, and clinically effective approach for cartilage repair.

Early reactive synovitis and osteolysis after total hip arthroplasty.

BACKGROUND: Little is known about intraarticular pathology following THA prior to the radiographic appearance of osteolysis, primarily due to imaging limitations. MRI has recently been applied to imaging the postarthroplasty hip with the ability to detect periarticular bony and soft tissue pathology; specifically, it is able to detect abnormal synovial patterns and focal bone loss well before the radiographic appearance of osteolysis. QUESTIONS/PURPOSES: We therefore used MRI to determine the incidence of early reactive synovitis and osteolysis in asymptomatic patients after THA, and whether there is an association between these MRI findings and clinical outcomes or radiographic wear measurements at this early stage. METHODS: We recruited 31 patients (33 hips) who underwent routine noncemented THA with one of three types of bearing surfaces: metal-on-cross-linked polyethylene (n = 7), ceramic-on-ceramic (n = 12), and ceramic-on-cross-linked polyethylene (n = 14). Patients underwent specialized MRI at a minimum of 12 months (mean, 23 months; range, 12-37 months) after surgery. MR images were analyzed for the presence of synovitis or osteolysis. WOMAC scores, patient assessment questionnaires, and radiographic wear measurements were correlated with MRI findings. RESULTS: Reactive synovitis was observed in 13 of 33 patients (39%) and focal osteolysis in one of 33 (3%). The presence of synovitis did not correlate with pain, activity level, patient satisfaction or clinical outcome scales, nor did it correlate with radiographic wear measurements at early followup. CONCLUSIONS: Our observations suggest reactive synovitis is common yet asymptomatic at short-term followup. We do not know either the etiology or the long-term implications of these observations.

Using magnetic resonance angiography to measure abnormal synovial blood vessels in early inflammatory arthritis: a new imaging biomarker?

OBJECTIVE: To ascertain whether magnetic resonance angiography (MRA) can reliably detect synovial neovascularization in subjects with early inflammatory arthritis. METHODS: Subjects with 6 weeks to 6 months of clinical evidence of inflammatory hand arthritis had a radiograph, power Doppler ultrasound (PDU) scan, magnetic resonance imaging (MRI), and contrast enhanced MRA performed on the more symptomatic hand. Ultrasound examination of the wrist and 2nd-5th metacarpophalangeal (MCP) joints was scored for erosions, synovial thickening, and synovial blood flow. MRI were assessed using the OMERACT Rheumatoid Arthritis MRI Score (RAMRIS). MRA was used to assess the number of abnormal vessels in the 2nd-5th MCP and in the wrist. RESULTS: Of 30 subjects, 66.7% showed abnormal vasculature on MRA in the MCP and/or wrist; mean number of abnormal vessels was 5.24 (range 0-22). Number of abnormal vessels on MRA was strongly correlated with degree of blood flow seen in the corresponding area on PDU (r = 0.79, p

The Maturation of Synthetic Scaffolds for Osteochondral Donor Sites of the Knee: An MRI and T2-Mapping Analysis.

OBJECTIVE: The purpose of this study was to analyze the morphological imaging characteristics and incorporation of TruFit bone graft substitute (BGS) plugs using cartilage-sensitive magnetic resonance imaging (MRI) and quantitative T2 mapping. DESIGN: Twenty-six patients (mean age, 28.72 years; range, 11-56 years) underwent osteochondral autologous transplantation (OATS) for chondral defects with filling of the knee joint donor sites using Trufit BGS plugs. The mean follow-up interval between implantation and MRI analysis was 21.3 months (range, 6-39 months). During this period, 43 cartilage-sensitive and 25 quantitative T2-mapping MRI studies were performed. The donor sites were assessed for plug and interface morphology, displacement, hypertrophy, subchondral edema, presence of bony overgrowth, percentage fill, and degree of incorporation. T2 relaxation times were measured for the superficial and deep layers of the repair tissue. A linear regression and correlational analysis was performed with Bonferroni correction, and P < 0.05 was defined as significant. RESULTS: Longitudinal analysis revealed favorable plug appearance at early follow-up (≤6 months), with 75% of plugs demonstrating flush morphology and 78% demonstrating near complete to complete fill. Plug appearance deteriorated at intermediate follow-up (~12 months), with only 26% of plugs demonstrating flush morphology and 52% with near complete or complete fill. Plug appearance substantially improved with longer follow-up (≥16 months), with 70% of plugs demonstrating flush morphology and 90% demonstrating near complete or complete fill. Interface resorption was common at ~12 months (P < 0.0001) and was associated with older age (P = 0.01) or a single-plug configuration (P = 0.04). T2 values for the repair cartilage approached that of normal cartilage with increasing duration after surgery (P < 0.004), more so for single- compared with multiple-plug configurations (P = 0.03). CONCLUSIONS: The Trufit BGS plug demonstrates a predictable pattern of postoperative maturation on MRI images that parallels its biological incorporation. An intermediate postoperative interval can be associated with unfavorable MRI findings. However, the plug appearance significantly improves with greater postoperative duration and has mean T2 relaxation times that approach those of normal articular cartilage.

A Review of Arthroscopic Bone Marrow Stimulation Techniques of the Talus: The Good, the Bad, and the Causes for Concern.

Osteochondral lesions of the talus are common injuries following acute and chronic ankle sprains. Numerous surgical treatment strategies have been employed for treating these lesions; arthroscopic bone marrow stimulation is recognized as the first-line technique to provide fibrocartilage infill of the defect site. While the short- and medium-term outcomes of this technique are good, the long-term outcomes are not yet known. An increasing number of studies, however, show a cause for concern in employing this technique, including declining outcome scores over time. The current authors have therefore developed a treatment strategy based on previously established guidelines in addition to morphological cartilage-sensitive fast spin echo techniques and quantitative T2 mapping magnetic resonance imaging (MRI). Accordingly, the authors advocate arthroscopic bone marrow stimulation in lesion sizes up to 8 mm in diameter and osteochondral autograft transplant (OATS) in lesion sizes greater than 8 mm in diameter. In the absence of long-term studies, confining the use of arthroscopic bone marrow stimulation to smaller lesions may support prolonged joint life by decreasing the rate at which the fibrocartilage ultimately degenerates over time. Employing the OATS procedure in larger lesions has the advantage of replacing "like with like." The current review examines the role of arthroscopic bone marrow stimulation techniques of the talus.

Traumatic Lateral Plantar Artery Pseudoaneurysm and the Use of Time-Resolved MR Angiography.

UNLABELLED: Vascular injury resulting in pseudoaneurysm formation in the plantar aspect of the foot is an uncommon injury after trauma. Such injuries are more often reported in the lateral plantar artery rather than the medial plantar artery, most likely because of its more superficial location. Traditional modalities in diagnosis have included ultrasound and digital subtraction angiography. We present a case of traumatic pseudoaneurysm of the lateral plantar artery following a foot laceration. Diagnosis was made by the use of high-resolution, time-resolved contrast-enhanced 3D magnetic resonance angiography, also referred to as "TRICKS" (time-resolved imaging of contrast kinetics). This technique provided high spatial resolution for the arterial anatomy as well as temporal resolution which allowed better delineation of the hemodynamic characteristics of the pseudoaneurysm. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1007/s11420-010-9170-3) contains supplementary material, which is available to authorized users.

An autologous cartilage tissue implant NeoCart for treatment of grade III chondral injury to the distal femur: prospective clinical safety trial at 2 years.

BACKGROUND: The healing potential of damaged articular cartilage is limited. The NeoCart is a tissue-engineered collagen matrix seeded with autogenous chondrocytes designed for the repair of hyaline articular cartilage. HYPOTHESIS: The NeoCart implant is well tolerated in the human knee. STUDY DESIGN: Case series; Level of evidence, 4. METHODS: Eight patients (treatment group) with full-thickness cartilage injury were treated with the NeoCart and evaluated prospectively. Autogenous chondrocytes provided by arthroscopic biopsy were seeded into a 3-dimensional type I collagen scaffold. The seeded scaffold was subjected to a tissue-engineering protocol including treatment with a bioreactor. Implantation of the prepared cartilage tissue patch was performed via miniarthrotomy and secured with a collagen bioadhesive. Evaluations through 24 months postoperatively included the subjective International Knee Documentation Committee questionnaire, visual analog scale, range of motion, and cartilage-sensitive magnetic resonance imaging (MRI), including quantitative T2 mapping. RESULTS: Pain scores after NeoCart implantation were significantly lower than baseline at 12 and 24 months after the procedure (P < .05). Improved function and motion were also noted at 24 months. Six patients had 67% to 100% defect fill at 24 months with MRI evaluation. One patient had moderate (33%-66%) defect fill, and another patient had poor (less than 33%) defect fill. Partial stratification of T2 values was observed for 2 patients at 12 months and 4 patients at 24 months. No patients experienced arthrofibrosis or implant hypertrophy. CONCLUSION: Pain was significantly reduced 12 and 24 months after NeoCart treatment. Trends toward improved function and motion were observed 24 months after implantation. The MRI indicated implant stability and peripheral integration, defect fill without overgrowth, progressive maturation, and more organized cartilage formation.

Magnetic resonance imaging in the diagnosis and management of hip pain after total hip arthroplasty.

Evaluation of pain following total hip arthroplasty (THA) can be challenging in the absence of radiographic pathology. This study aimed to examine the diagnostic utility of magnetic resonance imaging (MRI) in the evaluation of enigmatic hip pain following THA. We reviewed a series of patients who were evaluated with MRI after presenting with enigmatic hip pain following THA. MRI was able to demonstrate pathology in the periprosthetic tissues in all hips with minimal artifact. Patients underwent a range of conservative and operative interventions depending on the underlying pathology. If used discriminately in situations where pathology cannot be detected by conventional methods, MRI is a highly effective modality that can aid in the diagnosis of a wide range of disorders thereby allowing the clinician to determine the most appropriate intervention.

Magnetic resonance imaging and clinical evaluation of patellar resurfacing with press-fit osteochondral autograft plugs.

BACKGROUND: Autologous osteochondral transplantation (AOT) has been successfully used in the femoral condyle and trochlea and is an attractive treatment option for full-thickness patellar cartilage lesions. HYPOTHESIS: Patients treated with AOT for the repair of symptomatic, isolated patellar cartilage lesions will demonstrate improvement in functional outcomes and postoperative magnetic resonance imaging appearance. STUDY DESIGN: Case series; Level of evidence, 4. METHODS: Between 2002 and 2006, patients with focal patellar cartilage lesions treated with AOT were prospectively followed. The mean age at the time of surgery was 30 years. Clinical assessment was performed with the International Knee Documentation Committee (IKDC), activities of daily living of the Knee Outcome Survey (ADL), and Short Form-36 (SF-36) at baseline and most recent follow-up. Magnetic resonance imaging was used to evaluate the cartilage repair morphologic characteristics in 14 cases. RESULTS: Twenty-two patients met the study criteria with a mean follow-up of 28.7 months (range, 17.7-57.8 months). The mean patellar lesion size was 165.6 +/- 127.8 mm(2), and the mean size of the donor plug was 9.7 +/- 1.1 mm in diameter with 1.8 +/- 1.4 plugs/defect. The mean preoperative IKDC score was 47.2 +/- 14.0 and improved to 74.4 +/- 12.3 (P = .028). The mean preoperative ADL score was 60.1 +/- 16.9 and increased to 84.7 +/- 8.3 (P = .022). The mean SF-36 also demonstrated an improvement, from 64.0 +/- 14.8 at baseline to 79.4 +/- 15.4 (P = .059). Nine patients underwent concomitant distal realignment and demonstrated improvement between preoperative and postoperative outcomes scores, but these differences were not statistically significant. Magnetic resonance imaging appearance demonstrated that all plugs demonstrated good (67%-100%) cartilage fill, 64% with fissures < 2 mm at the articular cartilage interface, 71% with complete trabecular incorporation, and 71% with flush plug appearance. CONCLUSION: Patellar AOT is an effective treatment for focal patellar chondral lesions, with significant improvement in clinical follow-up. This study suggests that patients with patellar malalignment may represent a subset of patients who have a poor prognostic outlook compared with patients with normal alignment.

Imaging of the rotator cuff following repair: human and animal models.

Imaging of the rotator cuff following repair may be challenging due to the type of fixation, surgical manipulation of the tissue and the presence of residual defects that may exist in the presence of good functional outcome. Both ultrasound and magnetic resonance (MR) imaging present unique advantages in evaluation of the postoperative tissue. MR imaging has superior soft tissue contrast and provides a more global shoulder assessment, including the degree of arthrosis, while ultrasound enables a more dynamic testing of the repaired tissue. Power Doppler ultrasound and new contrast agents provide insight into the degree of vascular recruitment following repair.

Magnetic resonance imaging of joint arthroplasty.

Modification of MRI pulse sequence parameters has permitted imaging of arthroplasty and the surrounding soft tissue envelope, enabling detection of regional tendon attachments, including the hip abductors, the knee extensor mechanism, and the rotator cuff of the shoulder. The multiplanar capabilities and superior soft tissue contrast have established MRI as the most sensitive, noninvasive means to detect periacetabular osteolysis after hip arthroplasty. Detection of intrasynovial deposits that may precede bone loss and regions of neurovascular compression also is possible. An additional advantage is the lack of ionizing radiation, which is beneficial in serial examinations for the longitudinal assessment of particle disease.