Comparison of Knee Articular Cartilage Defect Size Between Measurements Obtained on Preoperative MRI Versus During Arthrotomy.

Background: Treatment decisions for cartilage defects are often based on lesion size. Magnetic resonance imaging (MRI) is widely used to diagnose cartilage defects noninvasively; however, their size estimated from MRI may differ from defect sizes measured during arthrotomy, especially after debridement to healthy cartilage if undergoing autologous chondrocyte implantation. Purpose/Hypothesis: The purpose of this study was to evaluate the reliability of 2 methods to assess knee cartilage defect size on preoperative MRI and determine their accuracy in predicting postdebridement defect sizes recorded during arthrotomy. It was hypothesized that defect size would be predicted more accurately by the total area of abnormal articular cartilage rather than the area of full-thickness cartilage loss as identified on MRI. Study Design: Cohort study (diagnosis); Level of evidence, 3. Methods: This study included 64 patients (mean age, 41.8 ± 9.6 years) who underwent autologous cell therapy. Each patient received a 3-T MRI at 6.1 ± 3.0 weeks before cell implantation. Three raters, a radiologist, a surgeon, and a scientist, measured (1) the full-thickness cartilage defect area and (2) the total predicted abnormal cartilage area, identified by an abnormal signal on MRI. Interrater reliability was assessed using the intraclass correlation coefficient (ICC). Actual pre- and postdebridement defect sizes were obtained from intraoperative surgical notes. Postdebridement surgical measurements were considered the clinical reference standard and were compared with the radiologist's MRI measurements. Results: Eighty-seven defects were assessed, located on the lateral (n = 8) and medial (n = 26) femoral condyle, trochlea (n = 17), and patella (n = 36). The interrater reliability of the cartilage defect measurements on MRI was good to excellent for the full-thickness cartilage defect area (ICC = 0.74) and the total predicted abnormal cartilage area (ICC = 0.78). The median full-thickness cartilage defect area on MRI underestimated the median postdebridement defect area by 78.3%, whereas the total predicted abnormal cartilage area measurement underestimated the postdebridement defect area by 14.3%. Conclusion: Measuring the full-thickness cartilage defect area on MRI underestimated the area to treat, whereas measuring the total abnormal area provided a better estimate of the actual defect size for treatment.

Histological and Radiological Assessment of Endogenously Generated Repair Tissue In Vivo Following a Chondral Harvest.

OBJECTIVE: To examine repair tissue formed approximately 15 months after a chondral harvest in the human knee. DESIGN: Sixteen individuals (12 males, 4 females, mean age 36 ± 9 years) underwent a chondral harvest in the trochlea as a pre-requisite for autologous chondrocyte implantation (ACI) treatment. The harvest site was assessed via MRI at 14.3 ± 3.2 months and arthroscopy at 15 ± 3.5 months (using the Oswestry Arthroscopy Score [O-AS] and the International Cartilage Repair Society Arthroscopy Score [ICRS-AS]). Core biopsies (1.8 mm diameter, n = 16) of repair tissue obtained at arthroscopy were assessed histologically (using the ICRS II and OsScore histology scores) and examined via immunohistochemistry for the presence of collagen types I and II. RESULTS: The mean O-AS and ICRS-AS of the repaired harvest sites were 7.2 ± 3.2 and 10.1 ± 3.5, respectively, with 80.3% ± 26% repair fill depth on MRI. The histological quality of the repair tissue formed was variable, with some hyaline cartilage present in 50% of the biopsies; where this occurred, it was associated with a significantly higher ICRS-AS than those with no hyaline cartilage present (median 11 vs. 7.5, P = 0.049). Collagen types I and II were detected in 12/14 and 10/13 biopsies, respectively. CONCLUSIONS: We demonstrate good-quality structural repair tissue formed following cartilage harvest in ACI, suggesting this site can be useful to study endogenous cartilage repair in humans. The trochlea is less commonly affected by osteoarthritis; therefore, location may be critical for spontaneous repair. Understanding the mechanisms and factors influencing this could improve future treatments for cartilage defects.

Pre-surgery exercise and post-operative physical function of people undergoing knee replacement surgery: A systematic review and meta-analysis of randomized controlled trials.

OBJECTIVE: To summarize the evidence regarding the effectiveness and dose-response characteristics of pre-operative exercise programmes on post-operative physical function following total knee arthroplasty. DATA SOURCES: CINAHL, Cochrane Library, PubMed, SPORTDiscus and EMBASE. STUDY SELECTION: Randomized controlled trials were eligible if they provided full description of physiological stress (i.e. mode, frequency, intensity and duration). DATA EXTRACTION: Data extraction and evaluation were performed by one reviewer. Methodological quality of the selected studies was assessed using the Physiotherapy Evidence Database scale. DATA SYNTHESIS: Twelve candidate studies were identified, but only 3 papers satisfied all inclusion criteria: 2 studies evaluated the effect of resistance training and 1 trial investigated proprioceptive training. The latter study elicited significantly enhanced post-operative gains in function for indices of standing balance (overall stability index: Hedges' g = -1; anteroposterior stability index: Hedges' g = -1.15; 6 weeks post-surgery). Results of meta-analysis based on the findings of 2 studies showed that, compared with controls, prehabilitative exercise involving resistance training offered no additional gains in isometric quadriceps muscle strength at 6 and 12 weeks post-operatively. CONCLUSION: Despite a potential for efficacy of exercise-based conditioning, this review highlights the scarcity of robust dose-response evidence to guide the formulation of total knee arthroplasty prehabilitation effectively.

Lateral meniscal cyst causing irreversible peroneal nerve palsy.

We report an unusual case of irreversible foot drop occurring secondary to a large lateral meniscal cyst. We discuss the presentation and management of this rare case and highlight some of the less common causes of foot drop.

Intraoperative assessment of acetabular orientation: technical note.

Acetabular surgery is frequently utilized to manage developmental dysplasia of the hip and hip problems associated with cerebral palsy. During the operation, accurate correction of the orientation of the acetabular fragment is necessary. We describe a technique that enables accurate assessment of the coronal plane alteration in orientation. Intraoperative image intensifier records were compared with postoperative films and the accuracy of the coronal plane correction was evaluated. We found the intraoperative sourcil angle closely correlated to the postoperative angle to within 1°. The Spearman correlation coefficient was R=0.97, suggesting a close relationship between the two measurements.

The Mayo Conservative Hip: experience from a district general hospital.

The Mayo Conservative Hip femoral prosthesis has been designed to optimise proximal femoral loading as well as preserving proximal femoral bone stock. Between October 2003 and May 2006, 42 patients (49 hips) underwent total hip replacement (THR) using the Mayo Conservative Hip femoral component. The mean age at operation was 57.8 years (range 44 to 74) and the mean clinical follow up was 3.1 years (range 2.3 to 4.7 years). The aim of our study was to review the short term results of this unorthodox femoral component. We found that 18% degrees of stems were malaligned >or= 5 degrees and the prevalence of intra-operative femoral fracture was 4%. We feel this prosthesis is difficult to implant and has an unacceptable fracture rate.