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.

Validity of Ultrasound Compared with Magnetic Resonance Imaging in Evaluation of Osteochondritis Dissecans of the Distal Femur in Children.

OBJECTIVE: Magnetic resonance imaging (MRI) is currently the gold standard to diagnose and monitor osteochondritis dissecans (OCD) of the knee. The purpose of this study was to evaluate for the first time if ultrasound imaging can be used to visualize osteochondritis dissecans of the distal femur. DESIGN: From May 2008 to December 2013, 44 children (26 boys and 18 girls) presenting with OCD of the knee in our department were examined and evaluated by ultrasound imaging. Mean age at diagnosis was 11.8 ± 2.2 years. Two independent experienced orthopedic surgeons analyzed the localization, stage, and the size of the OCD via ultrasound and compared the results with the MRI findings. RESULTS: Ultrasonic examination has limitations in assessing the OCD stage I and therefore is not suitable for evaluating this stage of the disease. In stages II to IV, a good correlation to MRI regarding defect localization and size can be found, when the defect is localized in a region that is accessible to ultrasonic examination. CONCLUSION: Ultrasonic scan is an appropriate tool for the screening and monitoring of OCDs stages II to IV. It provides an inexpensive and readily available alternative to MRI. In addition, the healing process of higher grade defects as well as the screening of the opposite side can also be performed by ultrasound. Detection of defects being localized close to the intercondylar notch or far posterior on the lateral condyle are limitations for the use of ultrasound.

Intra-articular osteoid osteoma in the proximal tibia and its imaging characteristics.

Due to mostly non-specific clinical symptoms and variable appearance on magnetic resonance imaging (MRI), the diagnosis of an intra-articular osteoid osteoma (iaOO) is often delayed. We report the case of a 26-year-old male with an atypical clinical manifestation of an iaOO in the proximal tibia and its MRI specific characteristics of tumor progression. The patient presented to our clinic after receiving multiple unsuccessful conservative and surgical interventions due to anterior knee pain, which persisted for 12months. Prior to the correct diagnosis of iaOO manifestation, the patient was subjected to multiple steroid infiltrations and two arthroscopies including partial meniscal resection. Due to increasing complaints, meniscal transplantation, bone decompression and/or ACL reconstruction were recommended. Subsequent computer tomography (CT) scanning and successful test medication with salicylates (ASS) confirmed iaOO presentation. Only after arthroscopic tumor resection was the patient symptom free at three months of follow-up. The present description of MRI specific characteristics of iaOO progression has the potential to accelerate correct tumor detection in the future.

"Fracturoscopy" is Superior to Fluoroscopy in the Articular Reconstruction of Complex Tibial Plateau Fractures-An Arthroscopy Assisted Fracture Reduction Technique.

OBJECTIVE: To analyze the anatomic accuracy of fracture reduction controlled by fluoroscopy as compared with arthroscopically assisted reduction ("fracturoscopy") in patients with complex tibial plateau fractures (AO/OTA 41-C). Quality of fracturoscopy-guided reduction was checked with postoperative computed tomography. DESIGN: Prospective observational study. SETTING: Urban level 1 trauma center. PATIENTS: Seventeen consecutive patients, with a complex, bicondylar tibial plateau fracture. INTERVENTION: The intraoperative, open insertion of an arthroscope (2.4-mm or 2.8-mm optics), to visualize the articular surface and fracture reduction. MAIN OUTCOME MEASUREMENTS: Ability to detect residual fracture depression or gap after previous open reduction under fluoroscopic guidance. RESULTS: An open fracture reduction with fluoroscopic guidance was performed in all cases. In 7 cases, open reduction and fluoroscopy resulted in satisfactory fracture reduction (fluoroscopy group). In 10 of 17 cases, subsequent "fracturoscopy" showed persistent fracture depression (≥2 mm, fracturoscopy group) with the need for intraoperative correction. Patients in the fracturoscopy group demonstrated significantly greater preoperative fragment depression (12.55 ± 6.56 mm) and a larger preoperative fracture gap (7.83 ± 5.49 mm) compared with patients with a satisfactory reduction under fluoroscopy (depression 4.97 ± 4.02 mm, P = 0.016; gap 2.47 ± 1.07 mm, P = 0.023). Fluoroscopy was not successful in achieving satisfactory reduction in cases in which the postero-latero-central region was affected (P = 0.004, χ test). Postoperative computed tomography demonstrated satisfactory articular reconstruction in all cases. CONCLUSIONS: Intraoperative fracturoscopy permitted a significantly improved visualization of fracture fragment displacement, specifically in the postero-latero-central region of the tibial plateau, as compared with fluoroscopy. Fracturoscopy is recommended for fractures involving the postero-latero-central region of the tibial plateau. LEVEL OF EVIDENCE: Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.

Intact bone vitality and increased accumulation of nonmineralized bone matrix in biopsy specimens of juvenile osteochondritis dissecans: a histological analysis.

BACKGROUND: Although commonly proposed to be the starting point of juvenile osteochondritis dissecans (JOCD), avascular osteonecrosis (AVN) has been an inconsistent finding in histological studies. Analysis of early-stage lesions is required to elucidate the origins of OCD and justify proper treatment. PURPOSE: To analyze histological sections of JOCD lesions with special emphasis on bone vitality. STUDY DESIGN: Cross-sectional study; Level of evidence, 3. METHODS: Of 64 patients with 74 JOCD lesions (20 females, mean age, 11.4 years; 44 males, mean age, 12.7 years), 34 required surgery because of lesion instability or failed nonoperative treatment. From 9 patients, 11 histological specimens were obtained. Lesions were classified according to the International Cartilage Repair Society (ICRS). Two additional histological control sections were harvested from children without JOCD manifestation. Undecalcified histological sections were histomorphometrically analyzed. To analyze the skeletal health of the patients, biochemical analyses with special emphasis on bone metabolism were performed. RESULTS: Histologically, no osteonecrosis was visible in any of the cases. Osteocyte distribution was similar among OCD lesions and controls. ICRS OCD I lesions (n = 6) showed no intralesional separation. In ICRS OCD II and III lesions (n = 5), there was a subchondral fracture concomitant with histological characteristics of active repair mechanism (increased bone formation: osteoid volume P = .008, osteoblast number P = .046; resorption: osteoclast number P = .005; and tissue fibrosis compared with controls). Instead, in ICRS OCD I lesions, subchondral osteoid volume (P = .010) and osteoblast number (P = .046) were significantly increased compared with controls; however, no active repair mechanisms (no increased bone resorption or fibrous tissue) were detected, suggesting a focal lack of mineralization. Fifty-seven of 64 patients (89.1%) showed a vitamin D deficiency. The median vitamin D serum level of the patients with ICRS OCD I lesions was 13.6 µg/L. CONCLUSION: In the present study, osteonecrosis was not found in histological specimens of JOCD. As a secondary finding, focal accumulations of nonmineralized bone matrix indicating a lack of mineralization in ICRS OCD I lesions were revealed. This finding correlated with a low level of vitamin D in the affected children.

Healing predictors of stable juvenile osteochondritis dissecans knee lesions after 6 and 12 months of nonoperative treatment.

BACKGROUND: Nonoperative treatment of stable juvenile osteochondritis dissecans (JOCD) lesions of the knee fails in up to 50% of cases. Healing predictors are needed to identify potential failures and thus determine treatment options. PURPOSE: A predictive model for healing potential after 6 and 12 months of nonoperative treatment of stable JOCD lesions based on sensitive magnetic resonance imagining (MRI) follow-up measurements was developed. STUDY DESIGN: Cohort study (diagnosis); Level of evidence, 2. METHODS: A retrospective cross-sectional study was conducted to analyze 62 white patients (76 stable JOCD lesions) who were initially treated by restriction of activity until they were free of pain. The primary end point was healing investigated on MRI with follow-up measurements after 6 and 12 months of nonoperative treatment. Multivariate logistic regression was used to determine the influence of age, sex, JOCD lesion size, clinical symptoms, and the occurrence of cystlike lesions (CLLs) on healing potential. Additionally, optimal prognostic cutoffs were defined to differentiate failures from nonfailures. RESULTS: After 6 months of nonoperative treatment, 51 (67%) of 76 stable JOCD lesions showed no progression toward healing or showed signs of instability. Normalized lesion width and area and CLL occurrence differed significantly between failures and nonfailures (P < .05). A multivariate logistic regression best-predictors model that included age, CLL size, and normalized lesion width best predicted healing after 6 months and resulted in an area under the curve (AUC) of 0.779 (P < .001). A cutoff at 48% healing probability, as predicted by a nomogram based on age, normalized lesion width, and CLL size, differentiated failures from nonfailures (sensitivity, 60.0%; specificity, 83.7%). After 12 months, 37 lesions (49%) had progressed toward healing, and the sole observation of CLL size had the highest predictive validity (AUC, 0.766). The optimal cutoff was a healing probability of 61% (lesion size, 1.3 mm; sensitivity, 70.3%; specificity, 74.1%). CONCLUSION: A 6-month period of nonoperative treatment with or without casting might be appropriate if the healing potential is >48%. A 12-month period of nonoperative treatment may be successful if the CLL is <1.3 mm in length as assessed on MRI.

Giant cell tumour of bone: reconstruction of the index metacarpophalangeal joint with an osteochondral graft from the lateral femoral condyle.

We describe the successful reconstruction of the index finger metacarpophalangeal joint with an osteochondral autograft from the lateral femoral condyle following failed curettage and cementation of a giant cell tumour of the proximal phalanx base. At the 2-year follow-up, a good functional outcome was noted with 0-80° range of motion of the metacarpophalangeal joint and no clinical or radiographic evidence of tumour recurrence.

Equestrian injuries caused by horse kicks: first results of a prospective multicenter study.

OBJECTIVE: To analyze horse-related accidents caused by hoof kicks. DESIGN: Prospective study to evaluate hoof kick-related accidents. SETTING: Multicenter study, including 9 trauma centers in Hamburg, Germany. PATIENTS: Patients who were treated as the result of a hoof kick between January 1, 2010, and May 1, 2010, were included in the study. MAIN OUTCOME MEASURES: Horse and rider qualifications, riders' use of protective equipment, location and activity at time of accident, mechanism of injury, injuries sustained, and treatment required for these injuries. RESULTS: Twenty-four equestrians received hoof kicks. The average age was 22.6 years (range, 7-34 years). All accidents (100%) occurred while the equestrians were handing or grooming the horse. Two riders (8.3%) wore a helmet at time of accident. Sixteen riders (66.7%) suffered orbital, midface, or mandible fractures; 8 riders (33.3%) had injuries on other parts of the body. CONCLUSIONS: Hoof kick injuries account for a significant proportion of equine injuries and occur when riders are dismounted, most frequently when grooming without wearing protective equipment. Head and facial injuries occur most frequently and suggest that mandatory helmet and facial grill use should be considered during all horse-related activities.

Anterior femoral epiphysiodesis for the treatment of fixed knee flexion deformity in spina bifida patients.

BACKGROUND: Fixed knee flexion deformity is a common problem in spina bifida patients. Owing to interference with ambulation, this deformity may lead to anterior knee pain and progressive crouch gait. If conservative treatment fails, surgical procedures including supracondylar femoral extension osteotomy, joint distraction, and posterior capsulotomy have to be considered. Potential complications of these procedures are fractures, neurovascular lesions, knee instability, and recurrent deformity with continued growth. As fixed knee flexion deformity in spina bifida patients frequently occurs bilaterally, this results in higher perioperative and postoperative risks and prolonged recovery, making these relatively invasive methods less appealing. In the skeletal immature patient, anterior femoral stapling is a feasible method to treat fixed knee flexion deformity as could be shown in an earlier study. In this study, anterior femoral stapling was performed in a series of patients with diverse etiologies, and the overall success rate was then calculated. The aim of this study was to determine whether anterior femoral epiphysiodesis may improve fixed knee flexion deformity in a group of spina bifida patients. METHODS: Ten spina bifida patients with bilateral fixed knee flexion deformity (20 knees) were treated by anterior femoral epiphysiodesis through stapling. None of the patients received further knee procedures. The mean preoperative fixed knee flexion deformity was 20.3 ± 9.9 degrees (range: 10 to 40 degrees). Clinical and radiographic follow-up examinations were performed every 3 to 6 months after surgery. RESULTS: All patients except 1 experienced significant improvement with a mean correction rate of 0.9 ± 0.5 degrees per month (range: 0.2 to 1.9 degrees). The residual flexion deformity averaged 5.3 ± 5.3 degrees (range: 0 to 15 degrees; P<0.001). CONCLUSIONS: Anterior femoral epiphysiodesis through stapling is an effective and safe method for the treatment of fixed knee flexion deformity in growing children and adolescents with spina bifida. LEVEL OF EVIDENCE: Therapeutic Study, Level IV.

The fate of osteochondral grafts after autologous osteochondral transplantation: a one-year follow-up study in a minipig model.

INTRODUCTION: Because articular cartilage shows little intrinsic capacity of spontaneous regeneration, a variety of treatment options are currently at use to repair cartilage damage. One of these is the autologous osteochondral transplantation (AOT). The aim of the present work was to study the histological changes during the progress of 1 year after AOT in the knee joint. MATERIALS AND METHODS: Twelve Minipigs underwent an AOT on the medial femoral condyles of both knees using cooled diamond studded trephines with a diameter of the grafts of 4.6 mm. Three animals were sacrificed at each 2, 8, 26 and 52 weeks after the operation. The condyles were analyzed histologically and immunohistologically for collagen types I and II. RESULTS: A successful bony incorporation was observed in all specimens. The transplant demonstrated an increasingly stable integration of the chondral matrix into the cartilage of the surrounding femoral condyle. At 52 weeks after the operations 5 of 6 condyles showed a chondral integration at least at one side of the graft. Immunohistologically all specimens showed physiological staining characteristics up to 52 weeks after operation. The quality of the chondral part of the graft showed a wide range of variations, ranging from vital tissue resembling native cartilage after 52 weeks, to severe degenerative signs beginning 2 weeks after operation and ending at 52 weeks with deep fissures fragmenting the cartilage and the complete loss of vital cells. CONCLUSION: The press-fit technique allows a stable bony incorporation. A chondral integration of the graft seems to occur, provided that a close contact between the interfaces can be achieved. Present results demonstrate a vital cartilagenous transplant for up to 52 weeks. However, some specimens showed in part severe degenerative signs. A possible explanation is an insufficient cooling of the trephines in relation to the small diameter of the grafts used in the minipig model. The collagen network seems not to be affected for up to 52 weeks.

Mechanical evaluation of different techniques for Achilles tendon repair.

INTRODUCTION: One aim of the surgical treatment of acute Achilles tendon ruptures is to obtain a maximum primary stability of the sutured tendon. Therefore, we investigated the primary stability of sutured human Achilles tendons depending on different applied techniques. METHODS: The strength of 60 repaired cadaveric human Achilles tendons was tested depending on either the suture technique (Bunnell or Kessler), the suture material (PDS-thread or PDS-cord) or an additional plantaris tendon augmentation (PDS-thread with or without augmentation). Following anatomic reconstruction the repaired specimens were loaded to failure. RESULTS: The use of Bunnell's technique resulted in a stronger primary suture stability compared to Kessler's technique. Sutures carried out with a PDS-thread were of lower strength than those accomplished with a PDS-cord (Bunnell: thread 139 N +/- 29.8; cord 291 N +/- 55.2/Kessler: thread 137 N +/- 37.3; cord 180 N +/- 41.1). Sutures performed according to Bunnell's technique with a PDS-thread and an additional autologous plantaris tendon augmentation reached the highest primary stability (326 N +/- 124.9). CONCLUSIONS: The findings identify the Achilles tendon suture with a PDS-cord according to Bunnell's technique as a mechanically strong method. A plantaris tendon augmentation in addition to a PDS-thread can even add more stability to the Achilles tendon suture.

Cultivation of three-dimensional cartilage-carrier-constructs under reduced oxygen tension.

Three-dimensional cartilage-carrier-constructs were produced according to a standard protocol from chondrocytes of an adult mini-pig. Experiments with different oxygen concentrations (21, 10 and 5%, v/v O(2)) were performed and the constructs were compared qualitatively and quantitatively. The appearance of the cartilage obtained under reduced oxygen tension seemed to be closer to native cartilage with respect to shape of the cells, distribution of the cells within the matrix, smoothness of the surface, etc. The thickness of the cartilage formed by free swelling was always in the same range as for native cartilage (approximately 1mm). Qualitatively the most stable attachment of the cartilage on top of the carrier was found for 10% O(2) (v/v). Especially at 5% O(2) (v/v) the attachment between cartilage and carrier was not sufficient. The constructs generated at lower oxygen tensions had a significantly higher amount of glycosaminoglycan per DNA, but still significantly less when compared to native cartilage. Furthermore, the cultivated cartilage contained a large amount of collagen type II. The experiments proved the applied concept for generation of cartilage-carrier-constructs and the usefulness of cultivation under reduced oxygen tension.

Bioreactor design for tissue engineering.

Bioreactor systems play an important role in tissue engineering, as they enable reproducible and controlled changes in specific environmental factors. They can provide technical means to perform controlled studies aimed at understanding specific biological, chemical or physical effects. Furthermore, bioreactors allow for a safe and reproducible production of tissue constructs. For later clinical applications, the bioreactor system should be an advantageous method in terms of low contamination risk, ease of handling and scalability. To date the goals and expectations of bioreactor development have been fulfilled only to some extent, as bioreactor design in tissue engineering is very complex and still at an early stage of development. In this review we summarize important aspects for bioreactor design and provide an overview on existing concepts. The generation of three dimensional cartilage-carrier constructs is described to demonstrate how the properties of engineered tissues can be improved significantly by combining biological and engineering knowledge. In the future, a very intimate collaboration between engineers and biologists will lead to an increased fundamental understanding of complex issues that can have an impact on tissue formation in bioreactors.

Bioreactor cultivation of three-dimensional cartilage-carrier-constructs.

A flow-chamber bioreactor was designed for generation of three-dimensional cartilage-carrier-constructs. A specific attribute of the flow-chamber is a very thin medium layer for improved oxygen supply and a counter current flow of medium and gas. Three-dimensional cartilage-carrier-constructs were produced according to a standard protocol from chondrocytes of an adult mini-pig. The final step of this protocol was performed either in the bioreactor or in 12-well plates. The bioreactor experiments showed a significantly higher matrix thickness but a lower ratio of glycosaminoglycan to DNA. For both culture methods the constructs contained a high amount of collagen II. Appearance of the cartilage obtained in the bioreactor seemed to be closer to native cartilage with respect to distribution of the cells within the matrix, smoothness of the surface etc. All results considered the flow-chamber bioreactor is a very useful tool for generation of three dimensional cartilage-carrier constructs.

RGD-peptides for tissue engineering of articular cartilage.

One keypoint in the development of a biohybrid implant for articular cartilage defects is the specific binding of cartilage cells to a supporting structure. Mimicking the physiological adhesion process of chondrocytes to the extracellular matrix is expected to improve cell adhesion of in vitro cultured chondrocytes. Our approach involves coating of synthetic scaffolds with tailor-made, cyclic RGD-peptides, which bind to specific integrin receptors on the cell surface. In this study we investigated the expression pattern of integrins on the cell surface of chondrocytes and their capability to specifically bind to RGD-peptide coated materials in the course of monolayer cultivation. Human chondrocytes expressed integrins during a cultivation period of 20 weeks. Receptors proved to be functionally active as human and pig chondrocytes attached to RGD-coated surfaces. A competition assay with soluble RGD-peptide revealed binding specificity to the RGD-entity. Chondrocyte morphology changed with increasing amounts of cyclic RGD-peptides on the surface.

Surgery of skeletal metastases.

During a period of 5 years, 74 female and 27 male patients with an average age of 63.3 years underwent a total of 117 operations for the management of impending ( n=41) or already existing ( n=76) pathologic fractures due to osseous metastases. The average stay in hospital was 17.8 days, and the average postoperative survival 15.8 months. The patients whose limbs were stabilized as a preventive measure were discharged 1.5 days earlier and survived surgery 5.9 months longer than the patients with pathologic fractures. The large percentage of female patients is due to the predominant role of mammary cancer (50%) and the comparatively long survival of patients after a primary diagnosis of this type of carcinoma. The other diagnoses involved were (in order of frequency): bronchial carcinoma (11%), hypernephroma (8%) and non-Hodgkin's lymphoma (8%). The metastases were mainly located at the proximal end or shaft of the femur (59.8%) and in the humerus (18.8%) so that in the majority of cases it was possible to implant weight-bearing prostheses or at least achieve enough stability to allow non-weight-bearing physiotherapy and thus early remobilization. The rate of systemic complications (excluding fatalities) was 14.5%. Local complications in the operated area occurred in 24.8% of cases. As a result, revision surgery was necessary in 10 cases (8.5%), and the fatality rate in hospital (6 weeks) was 7.9%. In view of the advanced stage of the disease in most of the patients, some of them with polypathia, we see these results as a basis for the generous indication for preventive stabilization of osseous metastases. Except in some cases, the primary intention of this therapy is not to cure the disease or prolong life but to improve the quality of life remaining for these patients while keeping their stay in hospital as short as possible and the rate of complications at an acceptable level.