Scott D. Weiner

Hazards of internal fixation in the treatment of slipped capital femoral epiphysis.

We reviewed the records of 202 patients (308 hips) in whom a slipped capital femoral epiphysis had been fixed with pins or screws. A serious complication that was directly related to the use of internal fixation developed in eighty hips (26 per cent). The rate of complications in the 202 patients was 40 per cent. In thirty-six (18 per cent) of the 202 patients, an additional procedure was done to correct a pin-related complication. Forty-one hip joints had been penetrated by a pin. Other complications included avascular necrosis (fourteen hips), chondrolysis (nine), fracture (one), infection (one), further slippage (one), sciatic-nerve injury (one), and breakage of a screw (eight). Ways of decreasing the incidence of complications of fixation were explored.

The characterization of "transient synovitis of the hip" in children.

A 30-year retrospective review of 497 cases of transient synovitis of the hip involving 475 children allowed full characterization of the syndrome. Femoral head measurements of 118 patients at follow-up of 6 months showed no significant dimensional changes. Three cases of Legg-Calvé-Perthes disease (2.5%) were found in follow-up, as well as a case of osteoid osteoma of the femoral neck and two cases of juvenile rheumatoid arthritis. Recurrent synovitis with a benign prognosis occurred in 19 patients. In spite of a generally anticipated good prognosis in the vast majority of cases, radiographic assessment at 6 months after the initial episode is recommended.

Primary human chondrocyte extracellular matrix formation and phenotype maintenance using RGD-derivatized PEGDM hydrogels possessing a continuous Young’s modulus gradient

Efficient ex vivo methods for expanding primary human chondrocytes while maintaining the phenotype is critical to advancing the sourcing of autologous cells for tissue engineering applications. While there has been significant research reported in the literature, systematic approaches are necessary to determine and optimize the chemical and mechanical scaffold properties for hyaline cartilage generation using limited cell numbers. Functionalized hydrogels possessing continuous variations in physico-chemical properties are, therefore, an efficient three-dimensional platform for studying several properties simultaneously. Herein we describe a polyethylene glycol dimethacrylate (PEGDM) hydrogel system with a modulus gradient (~27,000-3800 Pa) containing a uniform concentration of arginine-glycine-aspartic acid (RGD) peptide to enhance cell adhesion in order to correlate primary human osteoarthritic chondrocyte proliferation, phenotype maintenance, and extracellular matrix (ECM) production with hydrogel properties. Cell number and chondrogenic phenotype (CD14:CD90 ratios) were found to decline in regions with a higher storage modulus (>13,100 Pa), while regions with a lower storage modulus maintained their cell number and phenotype. Over 3 weeks culture hydrogel regions possessing a lower Youngs modulus experienced an increase in ECM content (~200%) compared with regions with a higher storage modulus. Variations in the amount and organization of the cytoskeletal markers actin and vinculin were observed within the modulus gradient, which are indicative of differences in chondrogenic phenotype maintenance and ECM expression. Thus scaffold mechanical properties have a significant impact in modulating human osteoarthritic chondrocyte behavior and tissue formation.

Osteochondritis dissecans involving the trochlea: report of two patients (three elbows) and review of the literature.

Osteochondritis dissecans (OCD) is an idiopathic lesion of subchondral bone resulting in separation of the articular cartilage and subchondral bone. Osteochondritis of the elbow primarily involves the capitellum. Only two cases involving the trochlea have been reported, one in the English literature and one in the German literature. Osteochondritis dissecans has been confused with other joint surface abnormalities, and therefore the orthopaedic literature must be read with scrutiny. Some of these other conditions include osteochondral fractures, osteonecrosis, accessory centers of ossification, and hereditary epiphyseal dysplasia. The authors describe two patients (one bilateral) with OCD involving the trochlea of the humerus. The first is a 12-year-old boy in whom an open biopsy was performed to rule out neoplastic lesions. The second is a 14-year-old boy with bilateral OCD that was recognized secondary to the similarity to the first patient. This patient was successfully treated conservatively. The first patient illustrates how recognition of OCD in the trochlea may prevent unnecessary biopsy. Osteochondritis dissecans should be part of the differential of lesions involving the trochlea.

Pitfalls in treatment of Legg-Calvé-Perthes disease using proximal femoral varus osteotomy

A femoral varus osteotomy can be used to contain the femoral head in Legg-Calve-Perthes (LCP) disease if certain pitfalls can be avoided. We reviewed 74 patients who underwent 79 femoral varus osteotomies. The study addressed the pitfalls that should be avoided with this technique. It was concluded that the amount of varus angulation should barely position the femoral head beneath the lateral rim of the acetabulum, avoiding varus < 105°, and that consideration should be given to performing a greater trochanteric epiphysiodesis at the time of initial femoral osteotomy. The short-term results reflect a positive attitude toward femoral varus osteotomy in treatment of LCP if these pitfalls can be avoided.

Potential for thermal damage to articular cartilage by PMMA reconstruction of a bone cavity following tumor excision: A finite element study

Benign, giant cell tumors are often treated by intralesional excision and reconstruction with polymethylmethacrylate (PMMA) bone cement. The exothermic reaction of the in-situ polymerizing PMMA is believed to beneficially kill remaining tumor cells. However, at issue is the extent of this necrotic effect into the surrounding normal bone and the adjacent articular cartilage. Finite element analysis (ABAQUS 6.4-1) was used to determine the extent of possible thermal necrosis around prismatically shaped, PMMA implants (8-24cc in volume), placed into a peripheral, sagittally symmetric, metaphyseal defect in the proximal tibia. Temperature/exposure time conditions indicating necrotic potential during the exotherm of the polymerizing bone cement were found in regions of the cancellous bone within 3mm of the superior surface of the PMMA implant. If less than 3mm of cancellous bone existed between the PMMA implant and the subchondral bone layer, regions of the subchondral bone were also exposed to thermally necrotic conditions. However, as long as there were at least 2mm of uniform subchondral bone above the PMMA implant, the necrotic regions did not extend into the overlying articular cartilage. This was the case even when the PMMA was in direct contact with the subchondral bone. If the subchondral bone is not of sufficient thickness, or is not continuous, then care should be taken to protect the articular cartilage from thermal damage as a result of the reconstruction of the tumor cavity with PMMA bone cement.

ECM production of primary human and bovine chondrocytes in hybrid PEG hydrogels containing type i collagen and hyaluronic acid

The development of advanced materials that facilitate hyaline cartilage formation and regeneration in aging populations is imperative. Critical to the success of this endeavor is the optimization of ECM production from clinically relevant cells. However, much of the current literature focuses on the investigation of primary bovine chondrocytes from young calves, which differ significantly than osteoarthritic cells from human sources. This study examines the levels of extracellular matrix (ECM) production using various levels of type I collagen and hyaluronic acid in poly(ethylene glycol) dimethacrylate (PEGDM) hydrogels in total knee arthroplasties, compared with the results from bovine chondrocytes. The addition of type 1 collagen in both the presence and absence of low levels of hyaluronic acid increased ECM production and/or retention in scaffolds containing either bovine or human chondrocytes. These findings are supported consistently with colorimetric quantification, whole mount extracellular matrix staining for both cell types, and histological staining for glycoaminoglycans and collagen of human chondrocyte containing samples. While exhibiting similar trends, the relative ECM productions levels for the primary human chondrocytes are significantly less than the bovine chondrocytes which reinforces the need for additional optimization.

Maximizing phenotype constraint and extracellular matrix production in primary human chondrocytes using arginine–glycine–aspartate concentration gradient hydrogels

New systematic approaches are necessary to determine and optimize the chemical and mechanical scaffold properties for hyaline cartilage generation using the limited cell numbers obtained from primary human sources. Peptide functionalized hydrogels possessing continuous variations in physico-chemical properties are an efficient three-dimensional platform for studying several properties simultaneously. Herein, we describe a polyethylene glycol dimethacrylate (PEGDM) hydrogel system possessing a gradient of arginine-glycine-aspartic acid peptide (RGD) concentrations from 0mM to 10mM. The system is used to correlate primary human osteoarthritic chondrocyte proliferation, phenotype maintenance and extracellular matrix (ECM) production to the gradient hydrogel properties. Cell number and chondrogenic phenotype (CD14:CD90 ratios) were found to decline in regions with higher RGD concentrations, while regions with lower RGD concentrations maintained cell number and phenotype. Over three weeks of culture, hydrogel regions containing lower RGD concentrations experience an increase in ECM content compared to regions with higher RGD concentrations. Variations in actin amounts and vinculin organization were observed within the RGD concentration gradients that contribute to the differences in chondrogenic phenotype maintenance and ECM expression.

Anterolateral approach to the hip for bone graft epiphysiodesis in the treatment of slipped capital femoral epiphysis.

In an effort to accommodate the needs of the majority of orthopedic surgeons who might encounter cases of slipped capital femoral epiphysis, an operative approach familiar to everyday practice was sought. Thirty-two cases of slipped capital femoral epiphysis were treated by bone graft epiphysiodesis using an anterolateral approach in contrast to the more traditionally used iliofemoral (Smith-Peterson) approach. Experience has shown this to be a better approach based on reduced operating time, less blood loss, avoidance of damage to the lateral femoral cutaneous nerve, improved wound healing, and for the operating surgeon, familiarity with an exposure utilized in total hip replacement.

On volunteerism and orthopaedics: AOA critical issues.

Sometimes give of your services for nothing. And if the opportunity for serving a stranger in financial straits, give full assistance to all such. For wherever the art of medicine is loved, there is also a love of humanity—Hippocrates As the quotation above suggests, the selfless giving of one’s services and time has been recommended by generations of medical leaders since medicine’s earliest emergence as a paid profession. Whether such recommendations are prescriptive (i.e., what a physician should do if he or she is so inclined) or descriptive (i.e., what a physician is obligated to do, given his or her skills, as part of being a physician) has long been a subject of debate. The philosophical center of the debate is whether health care is a “right”—regardless of one’s ability to pay for it or deliver himself or herself to a physician. For if it is indeed a “right,” we are obligated to provide care to all. One man’s right is another man’s moral and ethical obligation. In this spirit, a recent American Orthopaedic Association (AOA) symposium and round table discussion (at the 2012 annual meeting) explored whether volunteerism should be considered a “core competency” and, if so, how we might implement it as we do the other competencies outlined by the Accreditation Council for Graduate Medical Education (ACGME). It is our opinion that a careful reading of the currently accepted ACGME competencies indicates that volunteerism clearly falls under the “professionalism” umbrella and should be considered part of what we must do (and must teach) to be (and to produce) complete, competent orthopaedic surgeons. In an on-site survey, the audience felt strongly that role modeling by faculty is an important predictor of resident behavior. Although most of the audience felt neutral about incorporating an international elective in a resident curriculum, …