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Background The alignment of the lower extremity has important implications in the development of knee arthritis. The effect of incremental rotations of the limb on common parameters of alignment has not been studied. The purpose of the study was to (1) determine the standardized neutral position measurements of alignment and (2) determine the effect of rotation on commonly used measurements of alignment. Methods Eighty-seven full length CT angiography studies (49 males and 38 females, average age 66 years old) were included. Three-dimensional models were created using a rendering software program and placed on a virtual plane. An image of the extremity was obtained. Thirty scans were randomly selected, and those models were rotated in 3° intervals around the longitudinal axis and additional images were obtained. Results In the neutral position, the mechanical lateral distal femoral articular angle (mLDFA) was 85.6 ± 2.3°, medial proximal tibial angle (MPTA) was 86.1 ± 2.8°, and mechanical tibiofemoral angle (mTFA) was −0.7 ± 3.1°. Females had a more valgus alignment with a mTFA of 0.5 ± 2.9° while males had a more varus alignment with a mTFA of −1.7 ± 2.9°. The anatomic tibiofemoral angle (aTFA) was 4.8 ± 2.6°, the anatomic lateral distal femoral angle (aLDFA) measured 80.2 ± 2.2°, and the anatomical-mechanical angle (AMA) was 5.4 ± 0.7°. The prevalence of constitutional varus was 18%. The effect of rotation on the rotated scans led to statistically significant differences relative to the 0° measurement for all measurements. These effects may be small, and their clinical importance is unknown. Conclusions This study provides new information on standardized measures of lower extremity alignment and the relationship between discreet axial rotations of the entire lower extremity and these parameters.

Venous malformations are a subset of low-flow vascular malformations. These are usually present at birth and grow commensurate with the child. The treatment of low-flow vascular malformations has been studied extensively. Many interventions have been devised to benefit this patient population in regard to the pain, ulcerations, infections, cosmetic concerns, and overall bulk associated with these malformations. Treatment can begin with compression garments. Another treatment is sclerotherapy. This can be done as a stand-alone treatment or as an adjunct to surgical excision. Percutaneous sclerosis of venous malformations has an efficacy of between 74 and 90% in relieving symptoms. We present a case of percutaneous sclerotherapy with Sotradecol and ethanol into an extensive lower extremity venous malformation in the setting of orthopedic megaprosthesis. We feel that this led to extensive soft tissue necrosis and infection of the limb and created a precipitous situation.

We present 2 cases of cam/pincer combined femoroacetabular impingement treated arthroscopically with labral debridement, acetabuloplasty, and femoral head recontouring. In both cases there was essentially no evidence of osteoarthritis of the hip. However, in both cases raised exostoses were evident on the anterolateral femoral neck in the region that commonly comes into contact with the acetabular rim. On the basis of 3-dimensional dynamic reconstructions, we surmise that these exostoses are a direct result of linear contact between the femoral neck and acetabular rim. We recommend that the presence of these exostoses be carefully noted by the arthroscopic hip surgeon and that they be a geographic marker of the zone of contact between the head-neck junction and the acetabular rim and a guide for the area of head osteochondroplasty in combination with appropriate treatment of the acetabular rim.

Analysis of deformity and subsequent correction are the basis for many orthopaedic surgical procedures. In advanced cases of joint degeneration, arthroplasty may be the only available treatment option. Until recently, these analyses and preoperative surgical plans have been performed using standard radiographs, tracing paper, and/or plastic overlays. Numerous customized, commercially available, computer-based preoperative planning software programs have been introduced. The purposes of this study were to describe (1) the techniques used in deformity analysis and preoperative surgical planning using standard radiographs for joint arthroplasty and corrective osteotomies of the extremities, (2) the use of computed tomography (CT) scans to analyze rotational deformities in the presence and absence of joint prostheses and in planning corrective rotational osteotomies or revision joint replacement, and (3) the techniques for analyzing angular deformities of the spine. All these applications were performed with a widely available image analysis software.

PURPOSE: Recent advances in computer-modeling software allow reconstruction of facial symmetry in a virtual environment. This study evaluates the use of preoperative computer modeling and intraoperative navigation to guide reconstruction of the maxillofacial skeleton. METHODS: Three patients with traumatic maxillofacial deformities received preoperative, thin-cut axial CT scans. Three-dimensional reconstructions, virtual osteotomies, and bony reductions were performed using MIMICS planning software (Materialise, Ann Arbor, MI). The original and “repaired” virtual datasets were then imported into an intraoperative navigation system and used to guide the surgical repair. RESULTS: Postoperative CT scans and photographs reveal excellent correction of enophthalmos to within 1 mm in patient 1, significant improvement in symmetry of the nasoethmoid complex in patient 2, and reconstruction of the zygomaticomaxillary complex location to within 1 mm in patient 3. CONCLUSION: Computer modeling and intraoperative navigation is a relatively new tool that can assist surgeons with reconstruction of the maxillofacial skeleton. © 2007 American Academy of Otolaryngology–Head and Neck Surgery Foundation. All rights reserved.

Periprosthetic fractures involving a total knee arthroplasty pose a challenging treatment problem with a prevalence of up to 2.5% in the literature (Instr Course Lect 2001;50:379-389). The supracondylar region of the femur is commonly involved, often with minimal available bone in contact with the components. The clinical challenges are particularly more complex in the case of a combined distal femoral and proximal tibial periprosthetic fracture. This injury is considered a "floating prosthesis" injury because of the complete separation of the prosthesis from the remaining skeleton. In this report, a floating prosthesis injury, in combination with a femoral shaft fracture, is treated with 2 locking plates using a minimally invasive technique, with limited blood loss, immediate pain relief after surgery, and successful healing of all fractures with minimal deformity.

BackgroundThe treatment of osteochondritis dissecans in the adult knee can be challenging. As part of our comprehensive treatment program, fresh osteochondral allografts have been used in the surgical management of osteochondritis dissecans of the femoral condyle.HypothesisFresh osteochondral allograft transplantation will provide a successful surgical treatment for osteochondritis dissecans of the femoral condyle.Study DesignCase series; Level of evidence, 4.MethodsSixty-six knees in 64 patients underwent fresh osteochondral allografting for the treatment of osteochondritis dissecans. Each patient was evaluated both preoperatively and postoperatively using an 18-point modified D'Aubigné and Postel scale. Subjective assessment was performed using a patient questionnaire. Radiographs were evaluated preoperatively and postoperatively.ResultsMean follow-up was 7.7 years (range, 2-22 years). There were 45 men and 19 women with a mean age of 28.6 years (range, 15-54 years). All patients had undergone previous surgery. Forty-one lesions involved the medial femoral condyle, and 25 involved the lateral femoral condyle. All were osteochondritis dissecans type 3 or 4. The mean allograft size was 7.5 cm2. One knee was lost to follow-up. Of the remaining 65 knees, 47 (72%) were rated good/excellent, 7 (11%) were rated fair, and 1 (2%) was rated poor. Ten patients (15%) underwent reoperation. The mean clinical score improved from 13.0 preoperatively to 16.4 postoperatively (P < .01). Fifty-nine of 64 patients completed questionnaires. Subjective knee function improved from a mean of 3.4 to 8.4 on a 10-point scale (P < .01).ConclusionWith greater than 70% good or excellent results, fresh osteochondral allograft transplantation is a successful surgical treatment for osteochondritis dissecans of the femoral condyle.

Acetabular retroversion has been proposed to contribute to the development of osteoarthritis of the hip. For the diagnosis of this condition, conventional AP pelvic radiographs may represent a reliable, easily available diagnostic modality as they can be obtained with a reproducible technique allowing the anterior and posterior acetabular rims to be visible for assessment. This study was designed to: (i) determine cranial, central, and caudal anatomic acetabular version (AV) from cadaveric specimens; (ii) establish the validity and reliability of the radiographic measurements of central acetabular anteversion; and (iii) determine the validity and reliability of the radiographic "cross-over-sign" to detect acetabular retroversion. Using 43 desiccated pelvises (86 acetabuli) the anatomic AVs were measured at three different transverse planes (cranially, centrally, and caudally). From these pelvises, standardized AP pelvic radiographs were obtained. To directly measure central AV, a modified radiographic method is introduced for the use of AP pelvic radiographs. The validity and reliability of this radiographic method and of the radiographic cross-over-sign to detect cranial acetabular retroversion were determined. The mean central and caudal anatomic AVs were approximately 20 degrees , and the mean cranial AV was 8 degrees . Cranial retroversion (AV < 0 degrees ) was present in 19 of 86 hips (22%). A linear correlation was found between the central and cranial AV. Below 10 degrees of central AV, all acetabuli were cranially retroverted. Between 10 degrees and 20 degrees , 30% of the acetabuli were cranially retroverted, and above 20 degrees , only 1 of 45 acetabuli was cranially retroverted. The radiographic measurement of the central AV (20.3 +/- 6.5 degrees ) correlated strongly with the anatomic AV (20.1 +/- 6.4 degrees ). The sensitivity of the cross-over-sign to detect a cranial acetabular anteversion of less than 4 degrees was 96%, its specificity 95%, and the positive predictive and negative predictive values 90% and 98%, respectively. Both the modified radiographic anteversion measurements and the cross-over-sign demonstrated substantial inter- and intraobserver reliability. Retroversion is almost exclusively a problem of the cranial acetabulum. The cranial AV is on average 12 degrees lower than the central AV, with the latter directly measurable from AP pelvic radiographs. A central AV of less than 10 degrees was associated with cranial retroversion. The presence of a positive cross-over-sign is a highly reliable indicator of cranial AV of

Fresh osteochondral allografting is a nonvascularized organ transplantation with a clinical use dating back to the early twentieth century. The procedure, in its current form, involves transplantation of a small segment of bone as a carrier with its overlying cartilage. As the bone is remodeled and revascularized by the recipient, the donor cartilage continues to function mechanically, produces matrix, and receives nutrition from the synovial fluid. The cartilage has traditionally been considered a so-called immunoprivileged tissue, avoiding the immune surveillance of the host presumably because of its paucity of vascular channels and its hypo-cellular matrix1. These qualities make fresh osteochondral allografting unique in the field of transplantation and preclude the need for systemic immunosuppression after this procedure. Although histologically normal articular cartilage has been reported in retrieved fresh osteochondral allografts, we know of no report that has definitively confirmed the specific survival of the donor cells for any length of time. Furthermore, the source of cells in retrieved transplants has not been confirmed as being from the donor or the recipient. The patient was informed that data concerning his case would be submitted for publication. Atwenty-two-year-old man with a large defect on the articular surface of the lateral femoral condyle of the knee underwent fresh osteochondral allografting from a female donor. He recovered well from the allograft procedure and had a relatively pain-free knee for the next twenty-five years. He presented to us with knee pain on the lateral side and tricompartmental arthritis predominantly in the lateral compartment (Fig. 1). A magnetic resonance imaging scan was acquired, and it demonstrated a tear of the posterior horn of the lateral meniscus with loss of the articular cartilage thickness along the posterior aspect of the lateral femoral condyle (Fig. 2). He ultimately requested total knee …

Traditional advanced imaging modalities such as CT and MRI are limited in their ability to perform accurate linear distance and angular measurements regardless of anatomical orientation. The construction of 3D models has been used to perform anthropometric analyses as well as in the reconstruction of rapid prototypes. We hypothesized that such measurements would be precise to within 2 mm or 2 degrees of measurements performed with a coordinate measurement machine (CMM). We also hypothesized that there would be a high degree of interobserver reliability with these measurements.Multiple aluminum screws were implanted in various positions in three foam pelvises which were subsequently scanned by CT and rendered as 3D models using a commercially available software package (Mimics). Linear and angular measurements were performed using a CMM machine, the software package, and a dial caliper or goniometer. The deviation of the measurements from the CMM data was compared using ANOVA. The interobserver reliability of both the manual and computer-generated measurements was calculated.The mean difference between the CMM distances and those measured manually and with the software was 2.12 +/- 1.20 mm and 1.57 +/- 1.05 mm, respectively. The mean difference between the CMM angular measurements and the angular measurements performed manually and with the software was 4.07 +/- 4.70 degrees and 1.62 +/- 1.32 degrees, respectively. In all cases, the manual measurements were significantly less accurate (p0.0001) and there was a high degree of interobserver reliability.Computer-generated measurements taken from three-dimensionally reconstructed models are more accurate than manual measurements and are within 2 mm and 2 degrees of measurements performed with a CMM. These measurements have high interobserver reliability.

Periprosthetic supracondylar fractures of the femur after total knee arthroplasty represent a devastating complication for the patient and a technical challenge for the surgeon. Treatment is often complicated by advanced patient age, retained cement, and accompanying osteoporosis. We present the case of a 54-year-old woman with a comminuted fracture of the distal femur just above a total knee prosthesis. She had a complex past medical history, including extensive coronary artery disease, morbid obesity, chronic osteoporosis, anemia, diabetes, and rheumatoid arthritis. She was a Jehovah's Witness and thus refused all blood products. Given her medical history, religious preferences, and fracture comminution, a spanning external fixator was used. She completed fracture union with an excellent clinical and radiographic result at 2 years.

Background: Isolated revision of an acetabular total hip component is associated with special problems related to the retention of the femoral component. We reviewed the intermediate-term results of a series of such operations with use of the Harris-Galante Porous acetabular component. Methods: We retrospectively studied the results of ninety-five isolated acetabular revisions, specifically focusing on sixty-three that had been followed for a minimum of sixty months (average, 130 months). Evaluation measures included the Harris hip score, radiographic analysis, complications, and prosthetic survival. Follow-up information was obtained with self-administered questionnaires, telephone contact, and/or clinical examination. The effects of a femoral component with a modular neck-head junction and of trochanteric osteotomy on the dislocation rate were evaluated. Results: Nine shells were rerevised: four because of recurrent dislocation, four because of aseptic loosening, and one because of dissociation of the liner. The survival rate with rerevision of the shell as the end point was 90.5% at 120 months. Pelvic osteolysis occurred in 4% of the cases. The dislocation rate for the sixty-three hips was 8%. When femoral component modularity was accounted for, the analysis of the dislocations revealed a significantly higher dislocation rate for the hips without a trochanteric osteotomy (p = 0.04). Eight arthroplasties were complicated by nerve palsies, seven of which resolved fully or nearly so. Conclusions: Isolated acetabular revision with use of the Harris-Galante Porous acetabular component was associated with a low rate of loosening, lysis, and rerevision of the shell at the time of intermediate-term follow-up. However, there was a high rate of complications, including trochanteric nonunion, dislocation, and nerve palsy. The performance of a trochanteric osteotomy was associated with a decreased rate of dislocation. Level of Evidence: Therapeutic study, Level IV (case series [no, or historical, control group]). See Instructions to Authors for a complete description of levels of evidence.

Educational Objectives As a result of reading this article, physicians should be able to: 1. Identify the etiology of femoroacetabular impingement. 2. Assess femoroacetabular impingement on physical examination. 3. Recognize femoroacetabular impingement on imaging studies. 4. Discuss modern techniques to effectively treat femoroacetabular impingement, both open and arthroscopic. Femoroacetabular impingement (FAI) is a recently proposed concept describing abnormal anatomic relationships within the hip joint that may lead to articular damage. Impingement is caused by bony deformities or spatial malorientation of the femoral head-neck junction and/or the acetabulum. These abnormalities lead to pathologic contact and shearing forces at the acetabular labrum and cartilage during physiological hip motion. There is an increasing body of evidence that these forces lead to cartilage wear and eventual osteoarthritis. Treatment options for FAI are evolving rapidly. Although the gold standard remains open hip dislocation, arthroscopic techniques have shown significant promise. It is possible that early recognition and treatment of subtle deformity about the hip may reduce the rate of hip osteoarthritis in the future. [ Orthopedics. 2015; 38(3):185–199.]

Cam morphology in femoroacetabular impingement has been implicated in the development of osteoarthritis. The alpha angle and femoral head/neck offset are widely used to determine femoral head asphericity. To our knowledge, no study has evaluated the alpha angle circumferentially using three-dimensional imaging in a population of healthy individuals of adolescent age.We sought to (1) determine normal values for the alpha angle in adolescents, (2) define the location along the neck with the highest alpha angle, and (3) determine normal femoral head and neck radii and femoral head/neck offset.Fifty CT scans from a database of scans obtained for reasons not related to hip pain were studied. The average age of the subjects was 15 years (range, 14-16 years). Alpha angle and femoral head/neck offset were measured circumferentially.The alpha angle averaged 40.66 ± 4.46 mm for males and 37.77 ± 5.65 mm for females. The alpha angle generally was highest between the 11:40 and 12:40 o'clock and between the 6:00 and 7:40 o'clock positions. The femoral head radius was 24.53 ± 1.74 mm for males and 21.94 ± 1.13 mm for females, and the femoral neck radius was 16.14 ± 2.32 mm for males and 13.82 ± 2.38 mm for females. The mean femoral head/neck offset was 8.39 ± 1.97 mm for males and 8.13 ± 2.27 mm for females.In this healthy population of 14- to 16-year-old subjects, the highest alpha angle was at the superior and inferior aspects of the heads rather than at the anterosuperior aspect. This information will provide benchmark values for distinction between normal and abnormal morphologic features of the femoral head.

Defining pathologic widening of the pubic symphysis in the pediatric population continues to be a clinical challenge. The purpose of this study is to define a normal range of pubic symphyseal widths in various age and gender groups using axial computerized tomography (CT) scans.Axial CT images of 140 patients aged between 2 years and 15 years were obtained from our database of preexisting scans. Using a commercially available software package, the single image with the narrowest pubic symphyseal width was identified and measured. Patients were further stratified based on gender and by age into three groups: group A (age 2-5 years), group B (age 6-11 years), and group C (age 12-15 years).The mean width ± 95% confidence interval for all cases was 4.59 mm ± 0.18 mm. The mean width for male and female patients was 4.86 mm ± 0.26 mm and 4.33 mm ± 0.24 mm, respectively. Based on the two-way analysis of variance, both age group and gender had a statistically significant effect. Post hoc testing demonstrated a statistically significant difference in mean symphyseal width between groups A and C (p0.0001) and groups B and C (p = 0.0025) but not between groups A and B (p = 0.055). When grouped by age, the mean male pubic symphyseal width was found to be 5.10 mm, 4.93 mm, and 4.45 mm, while the mean female width was found to be 4.94 mm, 4.33 mm, and 3.54 mm at 2 to 6 years, 7 to 11 years, and 12 to 15 years of age, respectively.In the pediatric population, males seem to have a wider pubic symphysis than females of the same age group. In both males and females, pubic symphyseal width decreases during the transition from infancy toward skeletal maturity.Epidemiologic study, level III.

Fresh osteochondral allografts have been widely used to treat cartilage lesions for more than 100 years1. Transplantation of cartilage and bone in the form of an allograft allows osseous healing while maintaining the articular cartilage architecture. This composite tissue transplant remains intact in vivo for extensive periods of time with a favorable mechanical and biological environment. The chondrocytes of the graft are thought to actively remodel the extracellular matrix environment, and thus contribute to the tissue integrity. We recently reported that allograft cells could survive up to twenty-nine years after transplantation without the need for systemic immunosuppression2. Although mosaic cell populations have been demonstrated in other forms of transplantation, these have always been under the umbrella of long-term systemic immunosuppression3,4. In a classic study, Langer and Gross5 showed that intact articular cartilage surfaces obtained by removing the subchondral bone of rat femoral heads and filling of the osseous segments with acrylic cement exhibited essentially no humoral immune response in contrast to that seen with minced cartilage or isolated chondrocyte transplants. This finding has been attributed to the so-called “immunoprivileged” status of articular cartilage, which protects the chondrocytes from the immune system of the host. The extent to which allograft chondrocytes retain their gene expression profiles and chondrogenic capacities remains unknown. Our goal was to compare gene expression, proliferation rate, and chondrogenic potential between host and allograft chondrocytes isolated three years after an unsuccessful fresh osteochondral allograft transplant in the knee. The patient was informed that data concerning her case would be submitted for publication, and she provided consent. The study was performed in full compliance with our institutional review board (IRB). Our IRB at University of California Davis Medical Center does not consider case reports to be research and does not …

A low-contact stress, high-congruity, mobile-bearing patellofemoral joint arthroplasty decreases the contact force in the patellofemoral joint, theoretically reducing patellar polyethylene wear and increasing implant longevity. This article describes the case of a 47-year-old obese woman who presented with pain and loss of extension after a low-contact stress, high-congruity, mobile-bearing patellofemoral joint arthroplasty. Radiographs revealed dislocation (ie, spinout) of the patellar polyethylene. Patellar polyethylene spinout is a rare complication of metal-backed, mobile-bearing patellar resurfacing. Theoretically, patellar polyethylene spinout in low-contact stress, high-congruity, mobile-bearing patellofemoral arthroplasty is related to implant design and the placement of the metal base plate. Ultimately, the articulation of low-contact stress, high-congruity, mobile-bearing patellofemoral arthroplasty may be too congruent to resist the forces of the patellofemoral joint, particularly in patients who are obese, and the patellar rotation allowed by this articulation may not be sufficient for all patients. Should patellar spinout occur, replacement of the polyethylene is not sufficient to correct the problem; hence, revision of the patellar and trochlear components is required because it remains unclear whether failure is secondary to patellar or trochlear design deficiencies.

Background: This study was proposed to investigate the changes in the utilization of knee arthroscopy in an ambulatory setting over the past decade in the United States as well as its implications. Methods: The National Survey of Ambulatory Surgery, last carried out in 1996, was conducted again in 2006 by the Centers for Disease Control and Prevention. We analyzed the cases with procedure coding indicative of knee arthroscopy or anterior cruciate ligament reconstruction. To produce estimates for all arthroscopic procedures on the knee in an ambulatory setting in the United States for each year, we performed a design-based statistical analysis. Results: The number of arthroscopic procedures on the knee increased 49% between 1996 and 2006. While the number of arthroscopic procedures for knee injury had dramatically increased, arthroscopic procedures for knee osteoarthritis had decreased. In 1996, knee arthroscopies performed in freestanding ambulatory surgery centers comprised only 15% of all orthopaedic procedures, but the proportion increased to 51% in 2006. There was a large increase in knee arthroscopy among middle-aged patients regardless of sex. In 2006, >99% of arthroscopic procedures on the knee were in an outpatient setting. Approximately 984,607 arthroscopic procedures on the knee (95% confidence interval, 895,999 to 1,073,215) were performed in an outpatient setting in 2006. Among those, 127,446 procedures (95% confidence interval, 95,124 to 159,768) were for anterior cruciate ligament reconstruction. Nearly 500,000 arthroscopic procedures were performed for medial or lateral meniscal tears. Conclusions: This study revealed that the knee arthroscopy rate in the United States was more than twofold higher than in England or Ontario, Canada, in 2006. Our study found that nearly half of the knee arthroscopic procedures were performed for meniscal tears. Meniscal damage, detected by magnetic resonance imaging, is commonly assumed to be the source of pain and symptoms. Further study is imperative to better define the symptoms, physical findings, and radiographic findings that are predictive of successful arthroscopic treatment. Level of Evidence: Prognostic Level II. See Instructions to Authors for a complete description of levels of evidence.

A 39-year-old man presented with weakness and a nonmobile mass in the buttock of 5 months’ duration. Hip flexion was limited to 70°. Strength was diminished for both ankle/foot plantar and dorsiflexion. Sensation was decreased on the plantar and dorsal foot. A pedunculated osseous mass measuring 6×4 cm on the posterior femoral neck was seen on plain radiographs and magnetic resonance imaging. Electromyography showed moderate sciatic neuropathy of the peroneal and tibial branches. The patient underwent excision of the tumor through a posterior approach. Due to the risk of weakening the neck, two 7.3-mm cannulated screws were passed percutaneously into the head with fluoroscopic guidance. The final pathological report indicated the tumor was an osteochondroma. At 22-month follow-up, he had full resolution of the neurologic findings. Postoperatively, the patient reported improvement in numbness and tingling in the leg but continued to have moderate buttock pain. Left hip flexion increased to 115° at last follow-up. The importance of protecting the medial femoral circumflex artery during approaches to the hip is paramount. In this case, the tumor arose from the central aspect of the quadratus femoris, with the superior muscle protecting the medial femoral circumflex artery from harm. Although osteochondromas are a rare cause of mass effect, they should be considered in the differential diagnosis of sciatic nerve compression in this anatomical location.

This study is a retrospective evaluation of the intermediate-term results of 26 consecutive revision total hip arthroplasties performed with a modular titanium, uncemented femoral component. The average patient age at the time of revision total hip arthroplasty was 72 years, and there were an equal number of males and females. The mean follow-up was 5.7 years (ranging from 4 to 11 years). No re-revision was necessary during this follow-up time. The mean Harris hip score improved significantly (preoperative and postoperative score was 50.7 and 89.6, respectively; P < .001). Postoperatively, Short Form 36 functional scores averaged 67.7 across 9 functional parameters. Our observed low revision rate and favorable patient-reported outcome scores support the continuous use of modular titanium, uncemented femoral components in revision total hip arthroplasty.

In the setting of extraarticular deformities of the knee, total knee arthroplasty (TKA) is difficult, as anatomical abnormalities obstruct identification of alignment landmarks and may preclude the use of traditional instrumentation. The long-term clinical value of computer assistance for TKA is a point of ongoing controversy. Few reports describe the use of computer-assisted orthopedic surgery as a method to decrease alignment outliers in TKA with associated posttraumatic deformities. In this report, a 70-year-old woman who had a severe distal femoral deformity from a previous open fracture underwent computer-assisted TKA for osteoarthritis. The use of a computer-assisted navigation system achieved a high degree of accuracy relative to the desired target alignment and led to improved function in a patient in which standard instrumentation was not feasible.

Background Numerous structural deformities of the acetabulum are associated with hip osteoarthritis (OA). Acetabular retroversion has been implicated in the development of femoroacetabular impingement. However, it is unknown if retroversion occurs from isolated excessive bone in the superior acetabulum or a torsional phenomenon of the entire pelvic segment. Questions/purposes A method was developed to measure acetabular version (AV) using 3-D models thus eliminating positional factors. This method was used to determine if acetabular retroversion is an isolated entity or an effect involving the entire pelvic segment containing the acetabulum. Method Fifty pelvic CT scans were selected from a large database. Measurements were performed for abduction, ischial spine position, and AV at multiple levels. The relationships between anteversion at multiple levels and between midacetabular anteversion and ischial spine position were analyzed. Results The mean upper and midlevel acetabular anteversion values were 14.4° ± 10.5° and 21.3° ± 5.8°, respectively. The mean abduction was 39.7° ± 4.3°. The prevalence of acetabular retroversion was 7%. Females had greater anteversion than males at all levels. Correlations were found between Levels 1 and 4 version (r = 0.74) and the ischial spine index and Level 4 version (r = 0.67). Conclusions These data suggest retroversion involves the acetabulum at all levels and includes the entire pelvic segment containing the acetabulum and the ischial spine. Clinical Relevance These data are relevant for surgeons in providing targets for normal positioning of the acetabulum during periacetabular osteotomies and acetabular recontouring procedures.

Femoroacetabular impingement (FAI) has been recently established as a risk factor in the development of osteoarthritis of the hip. Intraosseous cysts are commonly seen on imaging of FAI. In most cases these cysts are incidental and do not require specific treatment at the time of surgical treatment of hip impingement. However, in some cases the cysts may mechanically compromise the acetabular rim or femoral neck. We present a technique for treating such cysts with an all-arthroscopic technique using a commercially available bone graft substitute composed of cancellous bone and demineralized bone matrix placed within an arthroscopic cannula for direct delivery into the cysts. This technique may be of benefit to surgeons treating FAI with an all-arthroscopic technique.

Posttraumatic osteoarthritis of the knee can be associated with angular deformities and alterations in the joint line as a result of the initial trauma and subsequent surgical procedures. These deformities can be characterized as extra-articular or intra-articular or can involve aspects of both. Conversion to total knee arthroplasty (TKA) may require either a staged or a simultaneous corrective osteotomy to restore the limb alignment and proper knee function. This article describes a closing wedge retrotubercular tibia osteotomy performed concurrently with TKA in an effort to correct an extra-articular varus deformity and to improve the patella tendon height in relation to the reconstructed joint line. A 57-year-old man previously treated for a Schatzker type 6 tibia plateau fracture presented with symptoms of arthritis pain and instability as a result of a varus thrust with weight bearing. Radiographs revealed posttraumatic osteoarthritis, a 35 degrees varus deformity, and patella infera. Maintaining the tibia tubercle continuity with the distal tibia allowed for correction of the varus deformity and improvement in the patella tendon height relative to the joint line. At 5-year follow-up, the patient had osteotomy healing, clinically neutral limb alignment, and improvement in joint line biomechanics with resolution of symptoms of pain and instability.

Unicompartmental knee arthroplasty (UKA) has a more than 30-year history in the treatment of arthritis of one compartment of the tibiofemoral joint. Despite early negative reports, the procedure has evolved into are liable and safe treatment. Successful outcomes withUKA require proper patient selection, meticulous surgical technique, and avoidance of deformity overcorrection.This procedure is indicated for patients with localized pain, preserved range of motion, and radiographically isolated tibiofemoral disease. UKA can provide more range of motion and improved patient satisfaction relative to total knee arthroplasty with comparable midterm longevity.

The accuracy and precision of any computer-aided surgical device is critical to its utility. We asked the following question: how accurate and precise are the values measured by an imageless computer navigation system as compared with those measured using postoperative CT scans? Twenty-five patients (26 hips) underwent primary THA using an imageless computer navigation system for placement of the acetabular component. Inclination and anteversion were measured in the operative coordinate system as defined by Murray. Accuracy, precision, and bias were computed, and Bland-Altman analysis was used to assess levels of agreement. The accuracy (mean +/- standard deviation of the absolute difference between computer-assisted navigation and CT) was 1.8 degrees +/- 1.2 degrees for inclination and 2.0 degrees +/- 2.0 degrees for anteversion. Precision was 3.4 degrees for inclination and 5.5 degrees for anteversion. Bias was 0.52 degrees for inclination and 0.35 degrees for anteversion. Limits of agreement were 4.26 degrees for inclination and 5.58 degrees for anteversion. An imageless computer navigation system can precisely determine acetabular cup position.

Twenty knees in 18 patients were treated (mean age, 42 years; range, 19-64 years) with fresh osteochondral allografting limited to the patellofemoral joint. The knees were analyzed retrospectively to determine the rate of successful outcomes. The trochlea and patella were treated in 12 patients and the patella was treated in eight patients. There were 11 women and seven men. The primary outcome measures were revision allografting, arthrodesis, or arthroplasty, and clinical scoring using a modified Merle D'Aubigné-Postel 18-point scale. Radiographs were available for 12 knees. There were five failures. For the remaining knees, the clinical scores increased from a mean of 11.7 points (range, 7-15 points) to 16.3 points (range, 12-18 points). Of the knees evaluated radiographically, four had no evidence of patellofemoral arthrosis, and six had only mild arthrosis. Fresh osteochondral allografting is a salvage procedure for the young, active patient with severe articular cartilage disease of the patellofemoral joint. The results of this procedure are comparable to results of described other techniques in the literature. If allograft incorporation does occur, the procedure is associated with improved pain, function, range of motion, and a low risk of progressive arthritis.Level IV (case series--no, or historical control group). See the Guidelines for Authors for a complete description of levels of evidence.

We report on tibiotalar osteochondral shell allografts for post-traumatic ankle arthropathy in seven patients. Average follow-up was 148 months (range, 85 to 198). Patients were evaluated by a questionnaire, SF-12 survey, ankle score, physical exam and radiographs. The ankle score increased from 25 preoperatively to 43 at latest follow-up (maximum score 100). SF-12 scores increased from 30 to 38 (Physical Component) and 46 to 53 (Mental Component). The failure rate was 42%. Four of seven patients reported good or excellent results. Five patients stated they would undergo a similar procedure again. Complications included graft fragmentation, poor graft fit, graft subluxation, and non-union. Follow-up radiographs demonstrated joint space narrowing, osteophytes, and sclerosis, even in cases with excellent clinical status. Fresh osteochondral shell allografting may provide a viable alternative for the treatment of post-traumatic ankle arthrosis in selected individuals.

Arthroscopically assisted reconstruction of the anterior cruciate ligament (ACL) is a common and effective method for treatment of anterior knee instability following ACL injury. Annually, an estimated 250,000 ACL injuries are diagnosed and approximately 100,000 ACL reconstructions are performed in the United States1-3. Chondrolysis is an extremely rare but devastating complication following ACL reconstruction. It is characterized by complete destruction of the articular cartilage and a profound inflammatory response consisting of pain, swelling, and loss of joint motion. The differential diagnosis includes osteonecrosis, direct trauma related to the injury or to the surgical procedure, infection, an adverse reaction to pharmacological agents (including local anesthetic infusions), and unknown causes. Infection after arthroscopic ACL reconstruction is rare: its incidence has been reported as 0.14% to 1.7%2,4-7. The most common causative organisms are Staphylococcus aureus, Staphylococcus epidermidis, and Staphylococcus haemolyticus 2,4-6. When tissue allografts have been used for ACL reconstruction, other organisms such as Peptostreptococcus, Klebsiella, Enterobacter, and Clostridium species as well as gram-negative bacilli have been implicated6,8. Although infrequent, infection can be a devastating complication that leads to septic arthritis, chondrolysis, osteomyelitis, osteochondral destruction, and, in rare cases, death2,5,8,9. We describe a case of medial tibial plateau osteochondral destruction secondary to an Aspergillus flavus fungal infection in an immunocompetent thirteen-year-old girl who had undergone elective ACL reconstruction. The patient and her parents were informed that data concerning the case would be submitted for publication, and they provided their consent. To the best of our knowledge, a case of Aspergillus fungal arthritis following ACL reconstruction has not been previously reported. Furthermore, salvage options outlined in the literature have been limited to primary arthrodesis, prosthetic reconstruction, use …