Clinical Orthopaedics and Related Research ®

A Publication of The Association of Bone and Joint Surgeons ®

Published in
Clinical Orthopaedics and Related Research®
Volume 467 | Issue 8 | Aug, 2009
Articles

Measurement of the Mechanical Properties of Bone: A Recent History

John Currey DPhil Much progress has been made in the last 50 years in our understanding of bone’s mechanical properties, and the reasons it has these properties and not others. The question is to what extent these advances have arisen from an increase in the techniques available for the study of bone, and how much stems from an increased understanding of the basic processes involved. Although considerable enlightenment has come from the transfer of ideas from the physical sciences, in particular materials science, the author argues that most increases have come from the vastly increased power and resolution of the observational and mechanical techniques available. Even so, the remarkably hierarchical nature of bone’s structure makes it an almost uniquely difficult material to understand properly, and much remains to be done to marry explanations at the macro-, micro- and nanolevels to obtain a full understanding of bone mechanics.

Trabecular Bone Mechanical Properties in Patients with Fragility Fractures

Jaclynn M. Kreider MS, Steven A. Goldstein PhD Fragility fractures are generally associated with substantial loss in trabecular bone mass and alterations in structural anisotropy. Despite the high correlations between measures of trabecular mass and mechanical properties, significant overlap in density measures exists between individuals with osteoporosis and those who do not fracture. The purpose of this paper is to provide an analysis of trabecular properties associated with fragility fractures. While accurate measures of bone mass and 3-D orientation have been demonstrated to explain 80% to 90% of the variance in mechanical behavior, clinical and experimental experience suggests the unexplained proportion of variance may be a key determinant in separating high- and low-risk patients. Using a hierarchical perspective, we demonstrate the potential contributions of structural and tissue morphology, material properties, and chemical composition to the apparent mechanical properties of trabecular bone. The results suggest that the propensity for an individual to remodel or adapt to habitual damaging or nondamaging loads may distinguish them in terms of risk for failure.

Monitoring the Mechanical Properties of Healing Bone

L. E. Claes PhD, J. L. Cunningham PhD Fracture healing is normally assessed through an interpretation of radiographs, clinical evaluation, including pain on weight bearing, and a manual assessment of the mobility of the fracture. These assessments are subjective and their accuracy in determining when a fracture has healed has been questioned. Viewed in mechanical terms, fracture healing represents a steady increase in strength and stiffness of a broken bone and it is only when these values are sufficiently high to support unrestricted weight bearing that a fracture can be said to be healed. Information on the rate of increase of the mechanical properties of a healing bone is therefore valuable in determining both the rate at which a fracture will heal and in helping to define an objective and measurable endpoint of healing. A number of techniques have been developed to quantify bone healing in mechanical terms and these are described and discussed in detail. Clinical studies, in which measurements of fracture stiffness have been used to identify a quantifiable end point of healing, compare different treatment methods, predictably determine whether a fracture will heal, and identify factors which most influence healing, are reviewed and discussed.

Type of Hip Fracture Determines Load Share in Intramedullary Osteosynthesis

Sebastian Eberle MS, Claus Gerber MS, Geert Oldenburg MS, Sven Hungerer MD, Peter Augat PhD The choice of the appropriate implant continues to be critical for fixation of unstable hip fractures. Therefore, the goal of this study was to develop a numerical model to investigate the mechanical performance of hip fracture osteosynthesis. We hypothesized that decreasing fracture stability results in increasing load share of the implant and therefore higher stress within the implant. We also investigated the relationship of interfragmentary movement to the fracture stability. A finite element model was developed for a cephalomedullary nail within a synthetic femur and simulated a pertrochanteric fracture, a lateral neck fracture, and a subtrochanteric fracture. The femur was loaded with a hip force and was constrained physiologically. The FE model was validated by mechanical experiments. All three fractures resulted in similar values for stiffness (462–528 N/mm). The subtrochanteric fracture resulted in the highest local stress (665 MPa), and the pertrochanteric fracture resulted in a lower stress (621 MPa) with even lower values for the lateral neck fracture (480 MPa). Thus, intramedullary implants can stabilize unstable hip fractures with almost the same amount of stiffness as seen in stable fractures, but they have to bear a higher load share, resulting in higher stresses in the implant.

Ability and Limitation of Radiographic Assessment of Fracture Healing in Rats

Yoshinobu Watanabe MD, PhD, Yu Nishizawa MD, Nobuyuki Takenaka MD, PhD, Makoto Kobayashi MD, PhD, Takashi Matsushita MD, DMsc [object Object]

Quantification of Fracture Healing from Radiographs Using the Maximum Callus Index

S. J. Eastaugh-Waring MB, ChB, FRCS, C. C. Joslin MB, ChB, FRCS, J. R. W. Hardy MD, FRCS, J. L. Cunningham PhD Callus formation and growth are an essential part of secondary fracture healing. Callus growth can be observed radiographically and measured using the “Callus Index,” which is defined as the maximum diameter of the callus divided by the diameter of the bone. We compared three groups of patients with tibial fractures treated by external fixation, intramedullary nailing, and casting to assess the validity of using serial measurements of callus index as a measure of fracture healing. When callus index was plotted against time for each patient, the point at which the fracture began to remodel, indicated by the highest point of the curve, was observed as a consistent feature regardless of fixation method. This occurred on average at 2½ weeks after plaster cast removal (14 weeks post injury), 5 weeks after external fixator removal (22 weeks post injury), and 27 weeks post injury for the intramedullary nailed fractures. Because remodeling only occurs once the fracture is stable, a peak in callus index is a reliable sign that the fracture has united. Serial measurements of callus index would therefore appear to offer a simple method of quantifying secondary fracture healing regardless of the treatment method used.,[object Object]

Parecoxib and Indomethacin Delay Early Fracture Healing: A Study in Rats

Sigbjorn Dimmen MD, Lars Nordsletten MD, PhD, Jan Erik Madsen MD, PhD Nonsteroidal antiinflammatory drugs (NSAIDs) are used to reduce inflammatory response and pain. These drugs have been reported to impair bone metabolism. Parecoxib, a specific COX-2 inhibitor, exerts an inhibitory effect on the mineralization of fracture callus after a tibial fracture in rats. Decreased bone mineral density (BMD) at a fracture site may indicate impairment of early healing, casting doubt on the safety of using COX-2 inhibitors during the early treatment of diaphyseal fractures. Forty-two female Wistar rats were randomly allocated to three groups. They were given parecoxib, indomethacin, or saline intraperitoneally for 7 days after being subjected to a closed tibial fracture stabilized with an intramedullary nail. Two and 3 weeks after surgery, the bone density at the fracture site was measured using dual energy xray absorptiometry (DEXA). Three weeks after the operation the rats were euthanized and the healing fractures were mechanically tested in three-point cantilever bending. Parecoxib decreased BMD at the fracture site for 3 weeks after fracture, indomethacin for 2 weeks. Both parecoxib and indomethacin reduced the ultimate bending moment and the bending stiffness of the healing fractures after 3 weeks. These results suggest COX inhibitors should be avoided in the early phase after fractures.

The Effects of Loading on Cancellous Bone in the Rabbit

Marjolein C. H. van der Meulen PhD, Xu Yang MD, Timothy G. Morgan PhD, Mathias P. G. Bostrom MD Mechanical stimuli are critical to the growth, maintenance, and repair of the skeleton. The adaptation of bone to mechanical forces has primarily been studied in cortical bone. As a result, the mechanisms of bone adaptation to mechanical forces are not well-understood in cancellous bone. Clinically, however, diseases such as osteoporosis primarily affect cancellous tissue and mechanical solutions could counteract cancellous bone loss. We previously developed an in vivo model in the rabbit to study cancellous functional adaptation by applying well-controlled mechanical loads to cancellous sites. In the rabbit, in vivo loading of the lateral aspect of the distal femoral condyle simulated the in vivo bone-implant environment and enhanced bone mass. Using animal-specific computational models and further in vivo experiments we demonstrate here that the number of loading cycles and loading duration modulate the cancellous response by increasing bone volume fraction and thickening trabeculae to reduce the strains experienced in the bone tissue with loading and stiffen the tissue in the loading direction.

Time of Return of Elbow Motion after Percutaneous Pinning of Pediatric Supracondylar Humerus Fractures

Lewis E. Zionts MD, Christopher J. Woodson MD, Nahid Manjra PA, Charalampos Zalavras MD The most common treatment for displaced pediatric supracondylar humerus fractures is closed reduction and percutaneous pinning. However, the time for return of elbow motion after treatment of these injuries is not well documented. To describe the return of elbow motion after closed reduction and percutaneous pinning of these fractures we retrospectively reviewed 63 patients (age range, 1.6–13.8 years) with displaced supracondylar fractures of the humerus stabilized with either two or three lateral entry pins. Pins were removed by 3 to 4 weeks. No patient participated in formal physical therapy. At each followup, elbow range of motion (ROM) was recorded for the injured and uninjured extremities. Elbow ROM returned to 72% of contralateral elbow motion by 6 weeks after pinning and progressively increased to 86% by 12 weeks, 94% by 26 weeks, and 98% by 52 weeks. After closed reduction and percutaneous pinning of a displaced, uncomplicated, supracondylar humerus fracture, 94% of the child’s normal elbow ROM should be expected by 6 months after pinning. Further improvement may occur up to 1 year postoperatively. This information may be helpful in advising parents what to expect after their child’s injury.,[object Object]

Vulnerable Neurovasculature with a Posterior Approach to the Scapula

Coen A. Wijdicks MSc, Bryan M. Armitage MSc, Jack Anavian MD, Lisa K. Schroder BS, MBA, Peter A. Cole MD Anatomic studies have described areas where there is no direct threat of inadvertent suprascapular nerve injury; however, these studies did not describe danger zones during open reduction and internal fixation of the fractured scapula. We therefore sought to define the topographic distribution in which these vulnerable structures most commonly are found, thus establishing danger zones. Twenty-four nonpaired cadaveric specimens were dissected. The infraspinatus and teres minor musculature were elevated off the posterior scapula body to reveal critical areas where the suprascapular neurovasculature and circumflex scapular artery were vulnerable to injury. We established radial coordinates to determine this relation to osseous landmarks. The mean distance from the spinoglenoid notch to the inferior border of the danger zone was 2.4 cm (range, 1.2–3.8 cm). The mean distance from the medial extent of the scapular spine to the medial border of the danger zone was 4.3 cm (range, 3.0–6.7 cm). The entry of the ascending branch of the circumflex scapular artery was located at the lateral border 5.6 cm (range, 4.5–7.0 cm) inferior to the spinoglenoid notch. These danger zones can aid the surgeon in determining the risk for suprascapular nerve injury, specifically with scapula fractures involving the spinoglenoid notch and/or lateral border.

Trans-upper-sternal Approach to the Cervicothoracic Junction

Yi-Lin Liu MD, Ying-Jie Hao MD, Tao Li MD, Yue-Ming Song MD, Li-Min Wang MD From August 1999 to February 2006, 11 patients with cervicothoracic lesions (eight males, three females; age range, 17–77 years) were surgically treated using the trans-upper-sternal approach. Combined cervicothoracic incision and upper sternotomy facilitated exposure for tumor resection, partial or subtotal removal of the involved vertebrae, and spinal cord decompression. The spinal column then was stabilized. Neurologic status was assessed using the Frankel classification. Followup for a minimum of 10 months (mean, 31 months; range, 10–56 months) revealed one patient had a chyle leak (50 mL) 1 day after surgery, which resolved after 2 days of drainage. One patient had a transient vocal cord paresis, which recovered within 3 months of surgery. All the patients had improved neurologic function. No nonunions or instrument-related complications developed. Stability of the vertebral column was maintained during followup in all patients. The trans-upper-sternal approach can provide excellent exposure for reconstruction of the cervicothoracic junction. Special care must be taken to avoid injury to the recurrent laryngeal nerve and the thoracic duct.,[object Object]

Six Sigma Analysis of Minimally Invasive Acetabular Arthroplasty: A Preliminary Investigation

David A. Heck MD, James B. Stiehl MD Minimally invasive techniques in THA may increase the difficulty of acetabular component insertion relative to the optimized position. We sought to determine the ability of eight surgeons to position an acetabular component placed using an anterior-lateral minimally invasive surgical (MIS) approach with conventional instruments or computer navigation using an optical imageless protocol compared with conventional true values determined by computed tomography (CT). We introduce a new approach, the Six Sigma process capability index, to assess outliers. Using the Six Sigma process capability index (Cp > 1.3) and the criteria of Lewinnek et al. of ± 10° for adequate precision, three-dimensional (3D) CT was capable for inclination and anteversion. Computer navigation and visual cues with conventional instrumentation were precise for anteversion but not for inclination. We conclude image-free computer navigation was not better than conventional instrumentation with the surgeons’ visual cues for acetabular cup placement. Six Sigma analysis allows comparison of various methods of referencing with literature controls, and our data suggest CT referencing is the most precise method.

Periacetabular Osteotomy: A Systematic Literature Review

John C. Clohisy MD, Amanda L. Schutz PhD, MPA, Lauren St. John BS, Perry L. Schoenecker MD, Rick W. Wright MD The Bernese periacetabular osteotomy is commonly used to treat symptomatic acetabular dysplasia. Although periacetabular osteotomy is becoming a more common surgical intervention to relieve pain and improve function, the strength of clinical evidence to support this procedure for these goals is not well defined in the literature. We therefore performed a systematic review of the literature to define the level of evidence for periacetabular osteotomy, to determine deformity correction, clinical results, and to determine complications associated with the procedure. Thirteen studies met our inclusion criteria. Eleven studies were Level IV, one was Level III, and one was Level II. Radiographic deformity correction was consistent and improvement in hip function was noted in all studies. Most studies did not correlate radiographic and clinic outcomes. Clinical failures were commonly associated with moderate to severe preoperative osteoarthritis and conversion to THA was reported in 0% to 17% of cases. Major complications were noted in 6% to 37% of the procedures. These data indicate periacetabular osteotomy provides pain relief and improved hip function in most patients over short- to midterm followup. The current evidence is primarily Level IV.,[object Object]

Patient Activity after Total Hip Arthroplasty Declines with Advancing Age

Stefan Kinkel MD, Nicole Wollmerstedt PhD, Jennifer A. Kleinhans, Christian Hendrich, Christian Heisel MD, PhD Evaluation of patient activity is essential for clinical decision making before THA. To correlate age progression to patient activity after THA, we determined the number of walking cycles of 105 patients in different age groups by decades. Patients on average performed 6144 walking cycles per day (2.24 million cycles per year). Men were more active than women. The highest activity occurred in patients between 50 and 59 years of age, with a constant decrease in activity with advancing age. However, within age groups, we observed up to sixfold differences in the number of walking cycles per day. In addition to declining activity with advancing age, higher body mass index correlated with lower step counts. The high mean measured number of walking cycles, which were even higher than those reported for subjects without an arthroplasty, suggests patients benefit from THA. Female gender, advanced age, and obesity correlated with lower activity. Owing to the high intragroup variability of our results, preoperative evaluation of patient activity levels, individual patient factors, and patient demands, should be considered in clinical practice.

THA with Highly Cross-linked Polyethylene in Patients 50 Years or Younger

Derek S. Shia MD, John C. Clohisy MD, Mark F. Schinsky MD, John M. Martell MD, William J. Maloney MD Highly cross-linked polyethylene has been associated with low in vitro wear, but also has decreased in vitro ultimate yield strength. We therefore asked whether highly cross-linked polyethylene would result in lower outcome scores, wear, or early failure in a young patient population. Seventy THAs in 64 patients were performed using a highly cross-linked (electron beam-irradiated to 9 Mrads) acetabular liner and a cobalt-chrome femoral head. The average age of the patients at surgery was 41 years (range, 19–50 years). The minimum followup was 2.4 years (average, 4 years; range, 2.4–6.5 years). We recorded demographic and clinical data, including Harris hip score. Polyethylene wear measurements were analyzed with a validated, computer-assisted, edge detection method. The average Harris hip score improved from 53 to 92 at last followup. There was no evidence of acetabular or femoral loss of fixation, subsidence, or loosening. Linear wear was undetectable at this followup interval. No patient experienced catastrophic failure or underwent revision surgery. These data show low polyethylene wear rates and no catastrophic failures at early followup in a young patient cohort.,[object Object]

Novel Measurement Technique of the Tibial Slope on Conventional MRI

Robert Hudek MD, Silvia Schmutz PhD, Felix Regenfelder MD, Bruno Fuchs MD, PhD, Peter P. Koch MD The posterior inclination of the tibial plateau, which is referred to as posterior tibial slope, is determined routinely on lateral radiographs. However, radiographically, it is not always possible to reliably recognize the lateral plateau, making a separate assessment of the medial and lateral plateaus difficult. We propose a technique to measure the plateaus separately by defining a tibial longitudinal axis on a conventional MRI. The medial plateau posterior tibial slope obtained from radiographs was compared with MR images in 100 consecutive patients with knee pain when ligament or meniscal injury was assumed. The posterior tibial slope on MRI correlated with those on radiographs. The mean posterior tibial slope was 3.4° smaller on MRI compared with radiographs (4.8° ± 2.4° versus 8.2° ± 2.8°, respectively). The reproducibility was slightly better on radiographs than MRI (± 0.9° versus ± 1.4°). Twenty-one of the 100 cases had more than a 5° difference (range, −8.7° to 8.9°) between the medial and lateral plateaus. The proposed technique allows measurement of the posterior tibial slope of the medial and lateral plateaus on a standard knee MRI. By using this novel measurement technique, a reliable assessment of the medial and lateral tibial plateaus is possible.,[object Object]

Normal Q-angle in an Adult Nigerian Population

Bade B. Omololu MBBS, FRCS, FWACS, Olusegun S. Ogunlade MD, FRCS, Vinod K. Gopaldasani MD The Q-angle has been studied among the adult Caucasian population with the establishment of reference values. Scientists are beginning to accept the concept of different human races. Physical variability exists between various African ethnic groups and Caucasians as exemplified by differences in anatomic features such as a flat nose compared with a pointed nose, wide rather than narrow faces, and straight rather than curly hair. Therefore, we cannot assume the same Q-angle values will be applicable to Africans and Caucasians. We established a baseline reference value for normal Q-angles among asymptomatic Nigerian adults. The Q-angles of the left and right knees were measured using a goniometer in 477 Nigerian adults (354 males; 123 females) in the supine and standing positions. The mean Q-angles for men were 10.7° ± 2.2° in the supine position and 12.3° ± 2.2° in the standing position in the right knee. The left knee Q-angles in men were 10.5° ± 2.6° in the supine position and 11.7° ± 2.8° in the standing position. In women, the mean Q-angles for the right knee were 21° ± 4.8° in the supine position and 22.8° ± 4.7° in the standing position. The mean Q-angles for the left knee in women were 20.9° ± 4.6° in the supine position and 22.7° ± 4.6° in the standing position. We observed a difference in Q-angles in the supine and standing positions for all participants. The Q-angle in adult Nigerian men is comparable to that of adult Caucasian men, but the Q-angle of Nigerian women is greater than that of their Caucasian counterparts.

Adaptation and Validation of Turkish Version of the Knee Outcome Survey-Activities for Daily Living Scale

Deniz Evcik MD, Saime Ay MD, Aral Ege PhD, Aycan Turel MD, Vural Kavuncu MD The Knee Outcome Survey-Activities of Daily Living Scale (KOS-ADLS), originally developed in English, is a valid and reliable self-reported instrument used for patients with various painful knee conditions. We adapted the KOS-ADLS to Turkish and tested its reliability and validity. We enrolled 142 patients with knee pain in the study. The patients were randomized into two groups: Group 1 (n = 75) completed the questionnaire twice a week for assessing test-retest reliability and Group 2 (n = 67) answered the questionnaire and performed additional tests for assessing validity. The intraclass correlation coefficient ranged from 0.98 to 0.99 with high internal consistency (Cronbach’s alpha, 0.89). Validity-related tests included pain measurement with a visual analog scale and functional tests, including time measurements for the get-up-and-go and ascending/descending stairs tests. The visual analog scale score correlated with total score (r = 0.56), function total score (r = 0.53), and symptom total score (r = 0.45). The ascending/descending stairs test correlated with total score (r = 0.47), function total score (r = 0.49), and symptom total score (r = 0.31). The get-up-and-go test weakly correlated with all three scores. The Turkish version of the KOS-ADLS is reliable and valid in evaluating the functional limitations of patients with knee pain.

Quantification of the Radiographic Joint Space Width of the Ankle

Berna Goker MD, Emel Gonen MD, Mehmet D. Demirag MD, Joel A. Block MD Quantification of joint space width of the ankle could provide information essential to evaluate the effects of potential disease-modifying agents and adverse effects of devices intended to ameliorate osteoarthritis elsewhere in the lower extremity. Current methods require proprietary software or have not been well validated; our purpose was to develop and assess the reliability of a digital joint space width quantification method using public access software. We studied 95 patients, asymptomatic in the ankles and without history of ankle trauma, but with symptomatic medial knee osteoarthritis, participating in an ongoing longitudinal trial. Weightbearing anteroposterior radiographs of the ankle and supine radiographs of the pelvis were assessed, and the narrowest medial and lateral tibiotalar joint space widths and hip joint space widths were measured using Image J software (US NIH, Bethesda, MD). Medial joint space widths were 2.56 ± 0.50 and 2.55 ± 0.48 mm, and lateral joint space widths were 2.45 ± 0.55 and 2.44 ± 0.52 mm, for right and left ankle, respectively. Coefficients of variation for repeat measurements by the same observer were 1.13% and 4.5%, and by different observers 7.30% and 7.27%, for medial and lateral joint space widths, respectively. Men had wider joint space widths than women when accounting for height. Joint space width of the ankle correlated with the joint space width of the hip and with height and weight, but not with age.

Scapulothoracic Arthrodesis in Facioscapulohumeral Dystrophy with Multifilament Cable

Mehmet Demirhan MD, Ozgur Uysal MD, Ata Can Atalar MD, Onder Kilicoglu MD, PhD, Piraye Serdaroglu MD Patients with facioscapulohumeral dystrophy (FSHD) are affected mostly by impaired shoulder function. Scapulothoracic arthrodesis was introduced to improve shoulder function. We evaluated the outcomes of scapulothoracic arthrodesis using multifilament cables, performed on 13 patients with FSHD (18 shoulders). There were eight males and five females (mean age, 29 years; range, 20–50 years). Outcome criteria were active shoulder forward flexion and abduction, the Disabilities of the Arm, Shoulder, and Hand (DASH) score, respiratory function tests, and a new shoulder function score. Patients were followed for a minimum of 24 months (average, 35.5 months; range, 24–87 months). Solid fusion was obtained in all shoulders (two after revision); active abduction range increased from 47.2° ± 11.6° to 102.2° ± 10.0° (mean ± standard deviation) and anterior flexion range from 55.6° ± 16.1° to 126.1° ± 20.9°. The DASH score decreased from 33.6 ± 8.9 points preoperatively to 11.6 ± 8.0 points postoperatively. Shoulder function score increased from 15.9 ± 2.4 points to 22.2 ± 1.3 points. Scapulothoracic arthrodesis provides satisfactory function in patients with FSHD. Our data suggest use of multifilament cables for fixation is a reasonable option with an acceptable complication rate.,[object Object]

Tibial Torsion in Cerebral Palsy: Validity and Reliability of Measurement

Sang Hyeong Lee MD, Chin Youb Chung MD, Moon Seok Park MD, In Ho Choi MD, Tae-Joon Cho MD Physical examinations of tibial torsion are used for preoperative planning and to assess outcomes of tibial osteomy in patients with cerebral palsy (CP). The thigh-foot angle (TFA) and transmalleolar axis (TMA) are commonly used, and the second toe test recently was introduced. However, the validity and reliability of the three methods have not been clarified. This study was performed to evaluate the validity and reliability of these physical measures. We recruited 18 patients (36 limbs) with CP. During reliability sessions, three raters with various levels of orthopaedic experience independently measured tibial torsion using the three different methods during one day before surgery. Validity was assessed by performing a correlation study between physical examination and two-dimensional computed tomographic (CT) findings. Interobserver reliability was greatest for the TMA followed by TFA and then by the second toe test with intraclass correlation coefficients of 0.92, 0.74, and 0.57, respectively. In terms of the concurrent validity, the correlation coefficients (r) for the CT measurements were 0.62, 0.52, and 0.55. When depicting tibial torsion by physical examination, all three methods had substantial validity, but test reliability and validity were highest for TMA measurements.,[object Object]

Extended Intralesional Treatment versus Resection of Low-grade Chondrosarcomas

Chad Aarons MD, Benjamin K. Potter MD, Sheila C. Adams MD, J. David Pitcher MD, H. Thomas Temple MD The need for segmental resection versus intralesional treatment of low-grade chondrosarcomas of the appendicular skeleton remains controversial. We hypothesized extended intralesional treatment would equally control malignant disease but with improved functional outcomes and decreased postoperative complications. We retrospectively reviewed 31 patients with 32 Grade I intracompartmental chondrosarcomas of the long bones of the appendicular skeleton treated with either resection (15 lesions) or extended intralesional curetting (17) at a minimum followup of 2 years (median, 55 months; range, 24–203 months). Lesions were larger and median followup was longer in the resection cohort. One local recurrence developed in each treatment cohort and neither transitioned to a higher grade of tumor. No patient had metastases develop or died of disease. The mean final Musculoskeletal Tumor Society functional scores were greater after extended intralesional versus resection treatment (29.5 versus 25.1). Complications were observed more frequently after resection and reconstruction (seven of 15) as compared with extended intralesional treatment (one of 17). Extended intralesional treatment of Grade I intracompartmental chondrosarcomas of the long bones of the appendicular skeleton therefore appears safe with improved functional scores and decreased complications versus segmental resection and reconstruction.,[object Object]

Treatment and Outcomes of Pelvic Malunions and Nonunions: A Systematic Review

Nikolaos K. Kanakaris MD, PhD, Antonios G. Angoules MD, Vassilios S. Nikolaou MD, PhD, George Kontakis MD, Peter V. Giannoudis MD, EEC(Orth) Although acute management of pelvic fractures and their long-term functional outcome have been widely documented, important information regarding malunion and nonunion of these fractures is sparse. Despite their relative rarity, malunions and nonunions cause disabling symptoms and have major socioeconomic implications. We analyzed the factors predisposing a pelvic injury to develop malunion/nonunion, the clinical presentation of these complications, and the efficacy of the reported operative protocols in 437 malunions/nonunions of 25 clinical studies. Treatment of these demanding complications appeared effective in the majority of the cases: overall union rates averaged 86.1%, pain relief as much as 93%, patient satisfaction 79%, and return to a preinjury level of activities 50%. Nevertheless, the patient should be informed about the incidence of perioperative complications, including neurologic injury (5.3%), symptomatic vein thrombosis (5.0%), pulmonary embolism (1.9%), and deep wound infection (1.6%). For a successful outcome, a thorough preoperative plan and methodical operative intervention are essential. In establishing effective evidence-based future clinical practice, the introduction of multicenter networks of pelvic trauma management appears a necessity.,[object Object]

Aseptic Forearm Nonunions Treated by Plate and Opposite Fibular Autograft Strut

Cesare Faldini MD, Stavroula Pagkrati MD, Matteo Nanni MD, Shay Menachem, Sandro Giannini MD Forearm nonunion frequently changes the relationship between the radius and ulna and may lead to impairment of forearm function. We propose a new surgical technique for aseptic forearm nonunions combining a fibular cortical autograft strut with a metal plate and a fibular intercalary autograft in cases with a segmental bone defect. We retrospectively reviewed 20 patients with a mean age of 31 years (range, 17–48 years) at the time of surgery. Minimum followup was 12 years (mean, 14 years; range, 12–21 years). There were no intraoperative or postoperative complications. At last followup, all forearm bones had remodeled. The mean visual analog pain scale was 1 (range, 0–3). Forearm function improved; there were no radiographic signs of ankle arthritis at followup. Surgical treatment of aseptic forearm nonunions by combining a massive fibular cortical autograft strut with a plate and associating a fibular intercalary autograft in case of a segmental bone defect led to bone healing, improved forearm function, and a durable outcome with long-term followup.,[object Object]

Pedicled Fasciocutaneous Flap of Multi-island Design for Large Sacral Defects

Yunqin Xu MScMed, Henglin Hai BMS, Zaiyue Liang BMS, Shuiyun Feng BMS, Caoyang Wang MScMed We designed a new pedicled fasciocutaneous flap for large sacral defects that combined a classic superior gluteal artery perforator flap and an acentric axis perforator pedicled propeller flap. We asked whether this technique would be simple and result in few complications. Six patients with large sacral defects had reconstruction using this technique in one stage. The size of the defect and postoperative complications in each patient were assessed. The minimum followup was 6 months (mean, 20.1 months; range, 6–38 months). All wounds healed with no recurrence during followup. Five patients achieved healing primarily, and another with minimal drainage achieved healing by secondary intention after a dressing change. No patients had deep infection, wound dehiscence, necrosis, or partial loss or shrinkage of the flap at final followup. The buttocks were symmetric. We consider this a good alternative for reconstructing large sacral defects because it is a relatively simple procedure and results in few complications.,[object Object]

Suspension Suture Augmentation for Repair of Coracoclavicular Ligament Disruptions

Tsan-Wen Huang MD, Pang-Hsin Hsieh MD, Kuo-Chung Huang PhD, Kuo-Chin Huang MD Surgical reconstruction of the coracoclavicular ligament is a fundamental part of management of high-grade acromioclavicular dislocations and Type II lateral third clavicular fractures. However, no single surgical procedure is fully satisfactory because of failure or complications. We present an alternative coracoclavicular stabilization technique, which avoids the use of hardware or tendon graft, that was used in 10 consecutive patients with complete coracoclavicular ligament disruptions. These patients were followed for a minimum of 14 months (average, 34.8 months; range, 14–55 months). At the final followup, functional outcome measurement instruments (University of California–Los Angeles shoulder rating system and Western Ontario Shoulder Instability Index) and radiographic analysis were adopted as the main outcome measures of shoulder function. The mean University of California–Los Angeles shoulder rating score and the mean Western Ontario Shoulder Instability Index aggregation score at 12 months after surgery were 33.8 (95% confidence interval, 32.8–34.8) and 93.4 (95% confidence interval, 88.2–98.6), respectively. The radiographic analysis revealed all patients had maintained reduction on radiographs at the final followup. These preliminary results suggest that this simple technique can achieve stable coracoclavicular reconstruction and facilitate healing of the repaired ligaments or fractures.,[object Object]

Tibia Adaptation after Fibula Harvesting: An in Vivo Quantitative Study

Fulvia Taddei PhD, Matteo Balestri MS, Eugenio Rimondi MD, Marco Viceconti PhD, Marco Manfrini MD Absence of the fibula after harvesting to reconstruct an upper-limb segment increases loads on the donor-side tibia and thereby provides a unique opportunity to analyze the bone adaptation process in humans. We therefore quantified densitometric and morphologic changes of the donor-side tibia in three young patients (ages 8, 13, 16 years), on the basis of computed tomography (CT) examinations of both legs (one preoperatively and two postoperatively). The range of final followup was 27–43 months. Three-dimensional models of shank bones were generated from CT data and used to measure cross-sectional area, diaphyseal cortical thickness, and cross-sectional moment of inertia. In addition, density of the newly formed bone was evaluated. The donor-side tibia showed morphologic and density adaptation with time. New bone was deposited predominantly in the interosseous space and almost replaced the bone area lost by excision of the fibula. The second moment of area grew more in the donor-side tibia than in the intact one, without fully recovering the contralateral tibia-fibula complex values, and the principal axes rotated toward the preoperative direction. Thus, while considerable adaptation had occurred by 27–43 months in these young patients, the adaptation was incomplete; the mineral density of the newly formed bone recovered normal cortical bone values only in the patient with the longest followup (43 months).,[object Object]

Different Differentiation of Stroma Cells from Patients with Osteonecrosis: A Pilot Study

Ching-Hua Yeh MS, Je-Ken Chang MD, Mei-Ling Ho PhD, Chung-Hwan Chen MD, Gwo-Jaw Wang MD Osteonecrosis (ON) is commonly caused by high doses of glucocorticoids or ethanol intake. We previously reported suppression of BMP-2 by dexamethasone was more pronounced and enhancement by lovastatin was less pronounced in bone marrow stromal cells (BMSCs) from patients with ON than from patients without ON. We therefore presumed the BMSCs might be dysfunctional in patients with ON and performed this pilot study. We obtained BMSCs from 10 patients with ethanol-induced ON, 10 patients with glucocorticoid-induced ON, and 12 patients without ON as control subjects, checking third passage cells for osteogenic and adipogenic gene expression and differentiation ability. BMSCs from patients with glucocorticoid-induced ON possessed less osteogenic gene expression and less osteogenic differentiation, whereas BMSCs from patients with ethanol-induced ON possessed more adipogenic gene expression and more adipogenic differentiation. Dysfunction of BMSCs may be one of the causes of ON, with differing dysfunction in ethanol-induced ON and glucocorticoid-induced ON. Glucocorticoids may possess more of a suppressive effect on osteogenesis than ethanol, whereas ethanol may possess a more potent adipogenic effect than glucocorticoids on BMSCs.

Treatment of War Wounds: A Historical Review

M. M. Manring PhD, Alan Hawk, Jason H. Calhoun MD, FACS, Romney C. Andersen MD The treatment of war wounds is an ancient art, constantly refined to reflect improvements in weapons technology, transportation, antiseptic practices, and surgical techniques. Throughout most of the history of warfare, more soldiers died from disease than combat wounds, and misconceptions regarding the best timing and mode of treatment for injuries often resulted in more harm than good. Since the 19th century, mortality from war wounds steadily decreased as surgeons on all sides of conflicts developed systems for rapidly moving the wounded from the battlefield to frontline hospitals where surgical care is delivered. We review the most important trends in US and Western military trauma management over two centuries, including the shift from primary to delayed closure in wound management, refinement of amputation techniques, advances in evacuation philosophy and technology, the development of antiseptic practices, and the use of antibiotics. We also discuss how the lessons of history are reflected in contemporary US practices in Iraq and Afghanistan.

Case Report: Locked Pubic Symphysis: An Open Reduction Technique

Lisa K. Cannada MD, Charles M. Reinert MD A locked pubic symphysis occasionally occurs after a lateral compression injury of the pelvic ring. One pubic bone becomes entrapped behind the contralateral pubis. Lateral compression pelvic injuries are well recognized, but a lateral compression pelvic injury resulting in a locked pubic symphysis is rare. We describe a locked pubic symphysis with greater than 4 cm overlap that was reduced with simple maneuvers and readily available instruments.

Case Reports: Heritable Thrombophilia Associated with Deep Venous Thrombosis after Shoulder Arthroscopy

Santiago L. Bongiovanni MD, Maximiliano Ranalletta MD, Agustin Guala MD, Gaston D. Maignon MD Thromboembolic complications after shoulder arthroscopy are rare and their cause has not been well determined. Heritable thrombophilia has been studied in relation to numerous clinical conditions, and it has been associated with thromboembolic complications after some orthopaedic surgeries, especially after total hip or knee arthroplasty. We report three patients who had deep vein thrombosis develop after shoulder arthroscopy. All three tested positive for heritable thrombophilia, a condition undetected until this complication occurred. This report highlights the possibility that unrecognized coagulation disorders might seriously influence the clinical outcome of minimally invasive surgery. We suggest heritable thrombophilia is a possible risk factor for or etiology of deep vein thrombosis after shoulder arthroscopy.
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