Magnetic resonance imaging of the meniscal roots.

The meniscal roots and supporting structures anchor the menisci to the tibial plateau and resist hoop stress, thereby preventing radial displacement of the menisci and secondary degenerative tibiofemoral compartment changes that may occur if this is compromised. The anatomy of the four meniscal roots and their supporting structures on magnetic resonance imaging (MRI) will be outlined in this review article, as well as the imaging appearances of meniscal root-related pathology, namely meniscal root degeneration and tears, meniscal extrusion and tibial plateau cystic lesions.

Magnetic resonance imaging of impingement and friction syndromes around the knee.

The knee is a complex joint with its function dependent on a combination of osseous and soft tissue structures. Alteration in the relationship of these tissues, due to either acute or chronic repetitive injury with possible underlying congenital predisposing factors, can result in impingement between the structures resulting in pain, particularly on activity. The purpose of this article is to provide a comprehensive review of the MRI features of various impingement syndromes around the knee.

Normal values of the axial patellotrochlear overlap on MRI: Good correlation with patellotrochlear index in patients with no patellofemoral pathology.

BACKGROUND: There are several imaging-based measurements for patellofemoral height, which are obtained from sagittal images. However, these methods can be misleading with sagittal oblique slices and when the patella is tilted and/or chronically subluxated. This study aimed to describe a simple method of measuring patellar height using axial patellotrochlear overlap (APTO) on MRI. METHODS: A retrospective observational study of 97 knees from 251 patients, excluding those with fractures, massive effusion, or patellofemoral conditions. APTO was measured as follows: (1) patellar length (P) - expressed as the number of axial images showing patellar articular cartilage; (2) trochlear overlap (T) - the number of axial images showing the overlap between patellar articular cartilage and articular cartilage of the lateral trochlea. APTO is the ratio T/P. All measurements were performed independently by six raters on two separate occasions. The raters were two orthopaedic consultants, one knee surgery fellow, two consultant musculoskeletal radiologists, and one radiology fellow. The conventional patellotrochlear index (PTI) was measured as a control for all patients by a senior musculoskeletal radiologist. RESULTS: The mean APTO value was 36.7% (range 14.2-66.6; standard deviation 11.4). There was a positive correlation with the PTI, Pearson correlation coefficient: 0.76, P < 0.001. Intra-observer reliability was good (intraclass correlation coefficient(ICC): 0.66, 95% confidence interval (CI) 0.54, 0.76, P < 0.001). Inter-observer reliability was fair (ICC: 0.51, 95% CI 0.41, 0.6, P < 0.001). CONCLUSIONS: APTO was shown to be a reliable measurement of patellar height and correlated with existing PTI for patellar height. Measurement of APTO on MRI could be a reliable alternative for the evaluation of patellar height. However, further studies are required to assess its validity in patients with patellofemoral pathology.

A Randomized Trial of Autologous Chondrocyte Implantation Versus Alternative Forms of Surgical Cartilage Management in Patients With a Failed Primary Treatment for Chondral or Osteochondral Defects in the Knee.

BACKGROUND: There are limited randomized controlled trials with long-term outcomes comparing autologous chondrocyte implantation (ACI) versus alternative forms of surgical cartilage management within the knee. PURPOSE: To determine at 5 years after surgery whether ACI was superior to alternative forms of cartilage management in patients after a failed previous treatment for chondral or osteochondral defects in the knee. STUDY DESIGN: Randomized controlled trial; Level of evidence, 1. METHODS: In total, 390 participants were randomly assigned to receive either ACI or alternative management. Patients aged 18 to 55 years with one or two symptomatic cartilage defects who had failed 1 previous therapeutic surgical procedure in excess of 6 months prior were included. Dual primary outcome measures were used: (1) patient-completed Lysholm knee score and (2) time from surgery to cessation of treatment benefit. Secondary outcome measures included International Knee Documentation Committee and Cincinnati Knee Rating System scores, as well as number of serious adverse events. Analysis was performed on an intention-to-treat basis. RESULTS: Lysholm scores were improved by 1 year in both groups (15.4 points [95% CI, 11.9 to 18.8] and 15.2 points [95% CI, 11.6 to 18.9]) for ACI and alternative, with this improvement sustained over the duration of the trial. However, no evidence of a difference was found between the groups at 5 years (2.9 points; 95% CI, -1.8 to 7.5; P = .46). Approximately half of the participants (55%; 95% CI, 47% to 64% with ACI) were still experiencing benefit at 5 years, with time to cessation of treatment benefit similar in both groups (hazard ratio, 0.97; 95% CI, 0.72 to 1.32; P > .99). There was a differential effect on Lysholm scores in patients without previous marrow stimulation compared with those with marrow stimulation (P = .03; 6.4 points in favor of ACI; 95% CI, -0.4 to 13.1). More participants experienced a serious adverse event with ACI (P = .02). CONCLUSION: Over 5 years, there was no evidence of a difference in Lysholm scores between ACI and alternative management in patients who had previously failed treatment. Previous marrow stimulation had a detrimental effect on the outcome of ACI. REGISTRATION: International Standard Randomised Controlled Trial Number: 48911177.

Conventional versus 'all-inside' anterior cruciate ligament reconstruction: a randomized controlled trial comparing hamstring strength and functional outcome.

Cite this article: Bone Joint Open 2020;1-11:706-708.

Has the modern design of Attune total knee replacement improved outcome in patients with isolated patellofemoral arthritis?

INTRODUCTION AND AIM: Modern knee replacements aim to improve patient function in arthritis affecting different compartments of the knee. This study evaluates the Patient Reported Outcome Measure (PROM) and functional outcome of a modern total knee replacement (Attune, DePuy) in patients with isolated patellofemoral arthritis. METHODS: A total of 50 consecutive patients with isolated unilateral patellofemoral arthritis having had Attune total knee replacements at a single institution between 2010 and 2016 were prospectively studied. Five patients who developed symptoms on the opposite side during the study and two patients lost to follow-up were excluded. One patient needed early revision for loosening, leaving a total of 42 patients to be followed up over a period of 4 years. The Oxford Knee score (OKS) and Knee Injury and Osteoarthritis Outcome Score (KOOS) recorded pre-operatively and at follow-up was compared. A Functional assessment at around 8 months after operation was undertaken. RESULTS: At average follow-up of 24 months the mean OKS score improved by 15 points and the KOOS score improved by 20 points. Final KOOS sub-score for Pain was 80, Symptom 80, and ADL 82, Sports & Recreation 32 and QOL 60. Functional assessment at mean 8 months showed that a significant number of patients were able to Kneel (50%); Sit cross legged (23%); sit on their heel (23%) and were able do a single leg dip test (86%). CONCLUSION: This unique study of a modern design total knee replacement (Attune) in patients with isolated unilateral patellofemoral arthritis shows good PROM scores at 2 years and good functional assessment results at 8 months. The PROM scores are marginally better than the published results with Attune's predecessor, in a similar cohort of patients, but falls short of the published results of patellofemoral replacement implants. Large randomised comparative studies between traditional and the modern implant design is recommended to answer the question if design modification has influenced clinical outcome in patients with patellofemoral arthritis.

Examination under Anesthesia in Patients with Recurrent Patellar Dislocation: Prognostic Study.

Surgical management of patellar instability is a matter of wide debate. While some authors believe that isolated medial patellofemoral ligament (MPFL) reconstruction is sufficient, others advocate procedures to treat the underlying pathology, namely, patella alta and trochlear dysplasia. Radiological studies have been traditionally used as a determinant of these pathologies and to determine the need for an additional procedure. The value of examination under anesthesia (EUA) in formulating a treatment plan remains unknown. Our aim is to assess the prognostic value of EUA in assessing patients presenting for surgical treatment of recurrent patellar dislocations. We retrospectively reviewed the outcome after surgical treatment of 23 patients who had undergone isolated MPFL reconstruction for recurrent patella dislocation by a single surgeon in our tertiary center. All data were completed at the time of index surgery. Primary outcome was recurrent instability requiring revision surgery. The mean age of the 23 patients undergoing MPFL reconstruction was 17.4 years of age. The median trochlea tuberosity-trochlear groove (TT-TG) distance was 15 mm with a median Caton-Deschamps ratio of 1.3. Of the 23 patients who underwent MPFL reconstruction, 9 failed (39%). Median time to failure was 10.5 months. All patients who failed MPFL reconstruction had a dislocating patella on EUA at >30 degrees of flexion. Radiological assessment of the knee to assess its morphology is essential for preoperative surgical planning for patients with recurrent patellar instability. Cutoff values to determine the need for surgical procedures require a consistent method of imaging and are prone to flaws in measurement. However, we demonstrated that EUA provides valuable additional information toward an appropriate surgical approach.Based on our small cohort, we suggest that patients in whom patella remains dislocated past 30 degrees of knee flexion on EUA are unlikely to benefit from isolated MPFL reconstruction.