Descriptive Epidemiology From the Research in Osteochondritis Dissecans of the Knee (ROCK) Prospective Cohort.

BACKGROUND: Osteochondritis dissecans (OCD) occurs most commonly in the knees of young individuals. This condition is known to cause pain and discomfort in the knee and can lead to disability and early knee osteoarthritis. The cause is not well understood, and treatment plans are not well delineated. The Research in Osteochondritis Dissecans of the Knee (ROCK) group established a multicenter, prospective cohort to better understand this disease. PURPOSE: To provide a baseline report of the ROCK multicenter prospective cohort and present a descriptive analysis of baseline data for patient characteristics, lesion characteristics, and clinical findings of the first 1000 cases enrolled into the prospective cohort. STUDY DESIGN: Cross-sectional study; Level of evidence, 3. METHODS: Patients were recruited from centers throughout the United States. Baseline data were obtained for patient characteristics, sports participation, patient-reported measures of functional capabilities and limitations, physical examination, diagnostic imaging results, and initial treatment plan. Descriptive statistics were completed for all outcomes of interest. RESULTS: As of November 2020, a total of 27 orthopaedic surgeons from 17 institutions had enrolled 1004 knees with OCD, representing 903 patients (68.9% males; median age, 13.1 years; range, 6.3-25.4 years), into the prospective cohort. Lesions were located on the medial femoral condyle (66.2%), lateral femoral condyle (18.1%), trochlea (9.5%), patella (6.0%), and tibial plateau (0.2%). Most cases involved multisport athletes (68.1%), with the most common primary sport being basketball for males (27.3% of cases) and soccer for females (27.6% of cases). The median Pediatric International Knee Documentation Committee (Pedi-IKCD) score was 59.9 (IQR, 45.6-73.9), and the median Pediatric Functional Activity Brief Scale (Pedi-FABS) score was 21.0 (IQR, 5.0-28.0). Initial treatments were surgical intervention (55.4%) and activity restriction (44.0%). When surgery was performed, surgeons deemed the lesion to be stable at intraoperative assessment in 48.1% of cases. CONCLUSION: The multicenter ROCK group has been able to enroll the largest knee OCD cohort to date. This information is being used to further understand the pathology of OCD, including its cause, associated comorbidities, and initial presentation and symptoms. The cohort having been established is now being followed longitudinally to better define and elucidate the best treatment algorithms based on these presenting signs and symptoms.

Sonographically Guided Posterior Cruciate Ligament Injections: Technique and Validation.

OBJECTIVE: To describe and validate a technique for sonographically guided posterior cruciate ligament (PCL) injections. DESIGN: Prospective, cadaveric laboratory investigation. SETTING: Procedural skills laboratory. SUBJECTS: Eight unembalmed, cadaveric, mid-thigh-knee specimens (4 left knees and 4 right knees) obtained from 4 male and 4 female donors aged 57 to 64 years (mean 60.8 years) with body mass indices of 27.7 to 36.5 kg/m(2) (mean 32 kg/m(2)). METHODS: A 5-2-MHz curvilinear probe and a 22-gauge, 78-mm stainless steel needle was used to inject 2 mL of diluted blue latex into the PCL of each specimen using an in-plane, caudad-to-cephalad approach. At a minimum of 24 hours postinjection, each specimen was dissected to assess the presence and distribution of latex within the PCL. MAIN OUTCOME: Presence and distribution of latex within the PCL. RESULTS: All 8 injections accurately delivered latex throughout the PCL, including the tibial and femoral footprints. In 2 of 8 specimens (25%), a small amount of latex was noted to extend beyond the PCL and into the joint space. No specimens exhibited evidence of needle injury of latex infiltration with respect to the popliteal neurovascular bundle, menisci, hyaline cartilage, or anterior cruciate ligament. CONCLUSIONS: Sonographically guided intraligamentous PCL injections are technically feasible and can be performed with a high degree of accuracy. Sonographically guided PCL injections should be considered for research and clinical purposes to deliver therapeutic agents into the PCL postinjury or postreconstruction.

Carpal coalition with radioscaphoid synostosis and hypoplastic thumb.

Carpal coalition is an anomaly that is usually discovered as an incidental finding on roentgenograms. The most common site is between the lunate and the triquetrum, though fusion of almost every combination of carpal bones has been reported. Carpal coalition can be isolated but has also been associated with numerous congenital malformation syndromes. In this article, we report the case of a 12-year-old boy with left-sided asymptomatic fusion of the trapezoid and trapezium, fusion of the radius and scaphoid, and hypoplasia of the thumb.

The effect of modern total knee arthroplasty on muscle balance at the knee.

Total Knee Arthroplasty (TKA) may affect the muscles operating at the flexion/extension (FE) or internal /external rotation (IE) axes. This study tested the hypothesis that a modern posterior stabilizing TKA will change the mechanical balance of the knee joint by altering the moment arms of muscles acting about two separate axes of rotation. Moment arms were determined for the normal knee, the knee after resection of the Anterior Cruciate Ligament (the ACL - knee) and the knee after a PCL-sacrificing TKA. Five fresh cadaver hemi pelvis specimens were used with 5 posterior stabilizing prostheses (a single model available from one manufacturer). Moment arms for the individual muscle tendons were multiplied by the muscle's tension fraction (fractional physiological cross-sectional area [PCSA]) to estimate its potential for moment production relative to the other muscles at the knee, and this value was labeled as the muscle's moment potential. Unlike earlier studies that looked at TKA across many manufacturers' types, this study concluded that there were no significant differences in muscle balance when comparing the intact knee and the posterior stabilized TKA.