Injectable autologous chondrocyte implantation in acetabular cartilage defects: 2-year minimum clinical and MRI results.

INTRODUCTION: Early results using injectable autologous chondrocyte implantation (ACI) for the treatment of full thickness acetabular cartilage defects have been promising. However, so far there is no information on radiological results after injectable ACI using spheroids. The purpose of this sturdy was to (1) investigate the quality of tissue repair on MRI and (2) investigate the correlation between the MRI results and clinical results at a minimum follow-up of 24 months after third generation ACI in full thickness acetabular cartilage defects. It was hypothesized that ACI shows good MRI results in patients with large full thickness acetabular cartilage defects 24 months after surgery. It was also hypothesized that there is a correlation between postoperative clinical and MRI morphological results at a minimum follow-up of 24 months. STUDY DESIGN: Retrospective case series. MATERIALS AND METHODS: Patients with ACI for full thickness acetabular cartilage defects > 2 cm2 were evaluated by preoperative and postoperative clinical scoring tools including the modified Harris Hip Score (mHHS), the International Hip Outcome Tool (iHOT-33), and the Subjective Hip Value (SHV) as well as a high resolution indirect arthro-MRI 24 months after surgery utilizing an identical imaging protocol for all patients. The magnetic resonance observation of cartilage repair tissue (MOCART) scoring system was used to classify the repair tissue on MRI. Demographic patient data was evaluated for influencing factors for pre- and postoperative clinical as well as radiological results. RESULTS: Thirty six consecutive patients (5 women/31 men, average age 32.9 years) had undergone two stage ACI procedure. The average size of the cartilage defect was 5.0 (2-6) cm2. The average follow-up was 29.9 (24-42) months. Four patients were not available for the final follow-up (follow-up rate 89%). The postoperative average MOCART score was 82.2 (± 14.2). MOCART score showed medium correlation of the item defect fill and the postoperative mHHS (r = 0.384, p = 0.043). There was no correlation of the other items or the total score with postoperative results. The patients showed significant improvement in the outcome measurements between preoperative and postoperative in the mHHS, the iHOT-33, and the SHV. CONCLUSIONS: Despite the large acetabular cartilage defects included in this study, ACI showed good MRI results with complete defect fill in 87.5% after a minimum 24-month follow-up. Statistically significant correlation of MRI and clinical results could only be seen with the item defect fill. Further research with longer follow-up is needed to evaluate the long-term results of ACI in acetabular cartilage defects.

Is the evaluation of the anterior inferior iliac spine (AIIS) in the AP pelvis possible? Analysis of conventional X-rays and 3D-CT reconstructions.

INTRODUCTION: A hypertrophic AIIS has been identified as a cause for extraarticular hip impingement and is classified according to Hetsroni using 3D-CT reconstructions. The role of the conventional AP pelvis X-ray, which is the first standard imaging step for the evaluation of hip pain, has not been investigated yet. MATERIALS AND METHODS: AP pelvis X-rays and 3D-CT reconstructions of patients were evaluated regarding their morphology of the AIIS. The conventional X-rays were categorized into three groups according to the projection of the AIIS: above (A) or below (B) the acetabular sourcil or even exceeding the anterior acetabular rim (C). They were compared to the morphologic types in the 3D-CT reconstruction (Hetsroni type I-III). RESULTS: Ninety patients with an equal distribution of type A, B or C projection in the AP pelvis were evaluated and compared to the morphology in the 3D-CT reconstruction. The projection of the AIIS below the acetabular sourcil (B + C) showed only moderate sensitivity (0.76) and specificity (0.64) for a hypertrophic AIIS (Hetsroni type II + III), but if the AIIS exceeds the anterior rim, all cases showed a hypertrophic AIIS in the 3D-CT reconstructions (Hetsroni type II + III). CONCLUSIONS: Distinct differentiation of the AIIS morphology in the AP pelvis is not possible, but the projection of the AIIS below the anterior acetabular rim represented a hypertrophic AIIS in all cases and should, therefore, be critically investigated for a relevant AIIS impingement.

Injectable autologous chondrocyte transplantation for full thickness acetabular cartilage defects: early clinical results.

INTRODUCTION: Acetabular cartilage lesions are frequently seen in young patients with hip pain and have been identified as an important prognostic factor. New therapies have complemented abrasion and microfracture procedures. The aim of the study is to evaluate the early outcome of patients with arthroscopic injectable autologous chondrocyte transplantations (ACT) for full thickness acetabular cartilage defects. METHODS: A two-step procedure ACT was performed in patients with full thickness acetabular cartilage defects measuring ≥2 cm(2). The patients were closely followed with clinical examination, pre- and postoperative scores until the latest available follow-up of 3, 6, 12, and 24 months. RESULTS: 20 consecutive cases (4 female, 16 male, mean age 33 years) were included. No patients were lost at final follow-up. The average defect size was 5.05 (range 2-6) cm(2). The average follow-up was 12.05 (range 6-24) months. Three months postoperatively the preoperative scores improved significantly from a mean mHHS of 63-81 points (p = 0.009), iHOT33 of 44-66 % (p = 0.028) and subjective hip assessment (Subjective Hip Value, SHV) of 60-87 % (p = 0.007). After 12 months the results improved significantly to a mean mHHS of 93 points (p = 0.017), an iHOT33 of 79 % (p = 0.007) and an SHV of 82 % (p = 0.048) compared with the preoperative scores. DISCUSSION: The injectable matrix associated ACT is a reliable procedure, yielding promising early results with a significant increase of all scores evaluated in patients with full thickness acetabular cartilage defects.

Correlation of the Subjective Hip Value with Validated Patient-Reported Outcome Measurements for the Hip.

BACKGROUND: The subjective hip value (SHV) was developed as a patient-reported outcome measurement (PROM) that is easily and quickly performed and interpreted. The SHV is defined as a patient's subjective hip measurement tool expressed as a percentage of an entirely normal hip joint, which would score 100%. The hypothesis is that results of the subjective hip value correlate with the results of the modified Harris hip score and the International Hip Outcome Tool in patients with hip-related diseases. METHODS: 302 patients completed the modified Harris hip score (mHHS), the International Hip Outcome Tool (iHot-33) as well as the SHV. The SHV consist of only one question: "What is the overall percent value of your hip if a completely normal hip represents 100%?". The patients were divided into five different groups depending on the diagnosis. Pearson correlation was used to evaluate the correlation between the different PROMs and linear regression analysis was used to calculate R2. RESULTS: 302 complete datasets were available for evaluation. There was a high correlation between the SHV and the iHOT-33 (r = 0.847; r2 = 0.692, p < 0.001) and the mHHS (r = 0.832; r2 = 0.717, p < 0.001). The SHV showed a medium (r = 0.653) to high (r = 0.758) correlation with the mHHS and the iHOT-33 in all diagnosis groups. CONCLUSION: The SHV offers a useful adjunct to established hip outcome measurements, as it is easily and quickly performed and interpreted. The SHV reflects the view of the patient and is independent of the diagnosis. Further research with prospective studies is needed to test the psychometric properties of the score.

Twenty-three neutrophil granulocytes in 10 high-power fields is the best histopathological threshold to differentiate between aseptic and septic endoprosthesis loosening.

AIMS: The histopathological diagnosis of infection in periprosthetic tissue from loose total joint endoprosthesis has been the subject of controversy. The aim was to define a histological criterion that would best differentiate between aseptic and septic endoprosthesis loosening. METHODS AND RESULTS: Neutrophilic granulocytes (NG) were enumerated histopathologically in 147 periprosthetic membranes obtained from aseptic and septic revision surgery, using periodic acid-Schiff (PAS) stains and CD15 immunohistochemistry. Cell numbers were correlated with the results of microbiological culture and the clinical diagnoses. Using receiver-operating characteristics, an optimized threshold was found at 23 NG in 10 high-power fields (HPF). Using this threshold, histopathological examination had a sensitivity of 73% and specificity of 95% when compared with microbiological diagnosis (area under the curve 0.881), and a sensitivity of 77% and specificity of 97% when compared with clinical diagnosis (area under the curve 0.891). CONCLUSIONS: We therefore recommend a counting algorithm with a threshold of > or =23 NG in 10 HPF (visual field diameter 0.625 mm) for the histopathological diagnosis of septic endoprosthesis loosening. If the enumeration of NG is difficult in conventional haematoxylin and eosin-stained slides, CD15 immunohistochemistry should be performed, whereas the PAS stain has not proven to be helpful.

Computer-assisted validation of the synovitis score.

Histopathological examination of synovial specimens can contribute to the diagnosis of chronic joint diseases. A so-called synovitis score has been introduced as a standardised grading system, based on the semi-quantitative evaluation of the three determining features of chronic synovitis: enlargement of synovial lining, density of synovial stroma and inflammatory infiltrate, giving a score between 0 and 9. The present study examines the reliability of this procedure by comparison with exact measurements using computer-assisted image analysis (CAIA). Seventy-one synovial specimens from patients with osteoarthritis (OA, n=22), psoriatic arthritis (PsA, n=7), rheumatoid arthritis (RA, n=35) and from a control group (Co, n=7) were evaluated using both the synovitis score and CAIA. The measurements were transformed to semi-quantitative values analogous to the synovitis score. The differences between the transformed CAIA scores and the pathologist's scores were 0 or +/-1 in 40 cases, whereas in 31 cases the difference was greater than 1 (correlation coefficient r=0.725). The CAIA scores differed significantly between Co and RA cases (p=0.000) as well as between OA and RA (p=0.000). We conclude that the synovitis score was validated by CAIA and can be regarded a reliable grading system that contributes to the diagnostic procedure of chronic joint inflammation.

Injectable autologous chondrocyte implantation (ACI) in acetabular cartilage defects-three-year results.

To evaluate the clinical outcome after arthroscopic matrix-associated injectable autologous chondrocyte implantation (ACI) in patients with large full-thickness acetabular cartilage defects. ACI was performed in young patients with full-thickness acetabular cartilage defects ≥2 cm2 in a two-step arthroscopic procedure. The patients were followed closely with clinical examinations and pre- and postoperative scores. The modified Harris Hip Score (mHHS), iHOT33 questionnaire (iHOT33) and the Subjective Hip Value (SHV) were surveyed. Demographic patient data was evaluated for influencing factors for the pre- and postoperative results. Thirty-two consecutive cases (4 female, 28 male, mean age 33 years) were included. The average defect size was 4.9 (range: 2-6) cm2. They were followed at 6, 12, 24 and 36 months postoperatively. Patients had improved significantly from 64 to 91 points (P < 0.001) in the mHHS, from 44% to 86% (P < 0.001) in the iHOT33 and from 54% to 87% (P < 0.001) in the SHV. No surgery related complications were noted. Cell cultivation failed in two cases (7%) and the patients decided for a repeated harvesting of cartilage cylinders followed by a successful ACI. Patients age and size of the cartilage defect showed no significant correlation with the pre- or postoperative results. Injectable ACI is a reliable procedure treating full-thickness acetabular cartilage defects leading to promising results 3 years postoperatively with a significant increase in all scores despite large acetabular cartilage defects in the weight-bearing zone.

Failed meniscus repair.

This report describes problems arising after an arthroscopic meniscal refixation using the biodegradable Clearfix screw system (Innovasive Devices, Marlborough, MA). A serious problem arose in the form of migration of a meniscal screw that had been inserted in accordance with the manufacturer's instructions. Dislocation of the screw led to pain on the medial aspect of the knee joint and irritation of the infrapatellar branch of the saphenous nerve. The case reported here is a first analysis of the potential complications associated with the use of this meniscal refixation system.