Estimation of Trochanteric Soft Tissue Thickness From Dual-Energy X-ray Absorptiometry

Low body mass index is considered to be an important risk factor for fractures in postmenopausal women, in part reflecting its association with lower bone mineral density (BMD). In contrast, obesity is thought to be protective against fracture because of higher BMD and reduced transmitted force of falls as a result of soft tissue padding. Dual-energy X-ray absorptiometry (DXA) is most widely used for the assessment of osteoporosis. We hypothesized that trochanteric soft tissue thickness, as measured directly on whole-body DXA scans, could be estimated using the regional measures of anteroposterior tissue thickness from hip and spine DXA. We identified 376 adult patients who underwent DXA evaluation of the lumbar spine, hip, and whole body at the same visit. The population was randomly divided into 2 equal-sized subgroups, one used to derive prediction equations for trochanteric soft tissue thickness and the other for independent validation. Compared with the actual measurement from the whole-body scans in the validation cohort, the DXA-based estimate gave an unbiased prediction of trochanteric soft tissue thickness (adjusted R² was 0.60 with a standard error of the estimate of 1.35 cm), which was significantly better than estimation obtained without DXA information (p < 0.001). Area under the curve discrimination for trochanteric soft tissue thickness in the lowest and highest tertiles was 0.901 (95% confidence interval: 0.849–0.953) and 0.859 (95% confidence interval: 0.805–0.915), respectively. Model-based prediction of trochanteric soft tissue thickness in the lowest and highest tertiles had sensitivities of 78.5% and 91.9% and specificities of 64.4% and 86.8%, respectively. We conclude that regional DXA scans of the spine and hip can be used to estimate the trochanteric soft tissue thickness.     

Enhancing dermal and bone regeneration in calvarial defect surgery

Introduction:

To optimize the functional and esthetic result of cranioplasty, it is necessary to choose appropriate materials and take steps to preserve and support tissue vitality. As far as materials are concerned, custom-made porous hydroxyapatite implants are biomimetic, and therefore, provide good biological interaction and biointegration. However, before it is fully integrated, this material has relatively low mechanical resistance. Therefore, to reduce the risk of postoperative implant fracture, it would be desirable to accelerate regeneration of the tissues around and within the graft.

Objectives:

The objective was to determine whether integrating growth-factor-rich platelet gel or supportive dermal matrix into hydroxyapatite implant cranioplasty can accelerate bone remodeling and promote soft tissue regeneration, respectively.

Materials and Methods:

The investigation was performed on cranioplasty patients fitted with hydroxyapatite cranial implants between 2004 and 2010. In 7 patients, platelet gel was applied to the bone/prosthesis interface during surgery, and in a further 5 patients, characterized by thin, hypotrophic skin coverage of the cranial lacuna, a sheet of dermal matrix was applied between the prosthesis and the overlying soft tissue. In several of the former groups, platelet gel mixed with hydroxyapatite granules was used to fill small gaps between the skull and the implant. To confirm osteointegration, cranial computed tomography (CT) scans were taken at 3-6 month intervals for 1-year, and magnetic resonance imaging (MRI) was used to confirm dermal integrity.

Results:

Clinical examination performed a few weeks after surgery revealed good dermal regeneration, with thicker, healthier skin, apparently with a better blood supply, which was confirmed by MRI at 3-6 months. Furthermore, at 3-6 months, CT showed good biomimetism of the porous hydroxyapatite scaffold. Locations at which platelet gel and hydroxyapatite granules were used to fill gaps between the implant and skull appeared to show more rapid integration of the implant than untreated areas. Results were stable at 1-year and remain so to date in cases where follow-up is still ongoing.

Conclusions:

Bone remodeling time could be reduced by platelet gel application during cranioplasty with porous hydroxyapatite implants. Likewise, layering dermal matrix over such implants appears to promote dermal tissue regeneration and the oshtemo mimetic process. Both of these strategies may, therefore, reduce the likelihood of postsurgical fracture by promoting mechanical resistance.KEY WORDS: Biomaterials integration, bone regeneration, cranioplasty, dermal matrix, platelet gel     

Fashioning of an anterolateral femoral bony lid for revision hip arthroplasty

Objective  Safe removal of a loosened or broken femoral stem together with cement particles and soft tissues. Preparation of the implant bed under direct vision and exact fitting of the new stem. Restoration of pain-free hip motion. Indications  Exchange of loosened or broken femoral stem, its simple extraction being impossible or fraught with complications and time-consuming. Contraindications  Exchange procedures that can be performed without resorting to an anterolateral bony lid. Surgical Technique  Anterolateral approach over the extent of the femoral stem plus cement plug. Fashioning of an anterolateral bony lid (approximately one third of the shaft circumference). The remaining part of the lateral cortex remains undisturbed. If at all possible, a proximal bony ring should be preserved. Distal part of the lid is shaped like a keel. Removal of stem, cement, granulation tissue, and necrotic bone. Reconstruction of the bed for the new femoral stem. All bony cavities are cleaned with a burr and filled with autogenous or allogenic bone. Insertion of revision stem protruding proximally by 1 cm. Closure of the lid. Stabilization with three cerclage wires. Final stable seating of the stem by gentle hammer blows. Results  This approach was used in 49 patients (average age 65 years [26–98 years]). Two patients died of unrelated causes, two could not be reached. The remaining 30 women and 15 men were followed up for 8.4 years (1–14 years). The average Harris hip score improved from 36 to 84 points. All osteotomies consolidated.     

The management of facial trauma

Facial or maxillofacial trauma occurs as a consequence of physical injury to the face and can include damage to soft tissue and bony structures either in isolation or combination. There is a male predominance with highest incidence in the age group of 20–40 years. The range of injuries include soft tissue damage, bruising, lacerations, burns and fractures of the underlying facial skeleton including the zygomatic complex, mandible, maxilla, orbit and nasoethmoidal complex. The concentration of special senses in the head and neck region means that even seemingly minor injuries can have a significant impact upon the long-term outcome for a patient. Careful assessment of an injured patient must include a full ATLS evaluation to ensure that associated potentially life-threatening injuries are not missed. This article describes the signs, symptoms and treatment of maxillofacial trauma, including management of hard and soft tissue trauma.     

Salvage of avascular bone from frostbite with free tissue transfer

Traditional management of frostbite injury of the hands and fingers has been to allow demarcation to occur between viable and nonviable tissues, corresponding to the level of amputation required. In this case report, phalangeal length in mummified digits was maintained with free tissue transfer followed by evidence of bony revascularization on bone scan. Rather than waiting for tissue demarcation to occur, the authors propose that consideration be given to debridement of soft tissues in the frostbitten fingers followed by free tissue transfer to salvage length and function in the digital bony skeleton.     

Apatite-coated silk fibroin scaffolds to healing mandibular border defects in canines

Tissue engineering has become a new approach for repairing bony defects. Highly porous osteoconductive scaffolds perform the important role for the success of bone regeneration. By biomimetic strategy, apatite-coated porous biomaterial based on silk fibroin scaffolds (SS) might provide an enhanced osteogenic environment for bone-related outcomes. To assess the effects of apatite-coated silk fibroin (mSS) biomaterials for bone healing as a tissue engineered bony scaffold, we explored a tissue engineered bony graft using mSS seeded with osteogenically induced autologous bone marrow stromal cells (bMSCs) to repair inferior mandibular border defects in a canine model. The results were compared with those treated with bMSCs/SS constructs, mSS alone, SS alone, autologous mandibular grafts and untreated blank defects. According to radiographic and histological examination, new bone formation was observed from 4 weeks post-operation, and the defect site was completely repaired after 12 months for the bMSCs/mSS group. In the bMSCs/SS group, new bone formation was observed with more residual silk scaffold remaining at the center of the defect compared with the bMSCs/mSS group. The engineered bone with bMSCs/mSS achieved satisfactory bone mineral densities (BMD) at 12 months post-operation close to those of normal mandible (p > 0.05). The quantities of newly formed bone area for the bMSCs/mSS group was higher than the bMSCs/SS group (p < 0.01), but no significant differences were found when compared with the autograft group (p > 0.05). In contrast, bony defects remained in the center with undegraded silk fibroin scaffold and fibrous connective tissue, and new bone only formed at the periphery in the groups treated with mSS or SS alone. The results suggested that apatite-coated silk fibroin scaffolds combined with bMSCs could be successfully used to repair mandibular critical size border defects and the premineralization of these porous silk fibroin protein scaffolds provided an increased osteoconductive environment for bMSCs to regenerate sufficient new bone tissue.     

In vivo behaviour of low-temperature calcium-deficient hydroxyapatite: comparison with deproteinised bovine bone

This study aims to evaluate in detail the biological osteoconductive properties of the low-temperature synthetic porous calcium-deficient hydroxyapatite and to compare it with the biological apatite. Bone reactions to granules of similar sizes of the low-temperature hydroxyapatite and commercially available non-sintered deproteinized bovine bone were compared. Two different temperatures were used to fabricate two batches of newly developed porous hydroxyapatite with different carbonate groups content and specific surface area. The histological analysis of specimens with histomorphometry was performed at different time after in vivo implantation. Based on histological analysis, the level of bone formation in the spaces between the implanted granules and through the interconnected pores of all implanted materials within a cortical region (bone area ingrowth 72–85 %) was several-fold higher than within a cancellous bone site (bone area ingrowth 16–28 %) at three and six months after implantation. Within the cancellous bone site, bone coverage of the implanted material at six months was significantly higher in hydroxyapatite material fabricated using low-temperature synthesis and subsequent processing at 150°C than in hydroxyapatite scaffold developed using low-temperature synthesis with subsequent processing at 700°C or deproteinized bovine bone. According to our study, the bioactive properties of the low-temperature calcium-deficient hydroxyapatite are comparable with the biological apatite. The favourable influence of a high specific surface area of a low-temperature calcium-deficient hydroxyapatite on in vivo bone formation was emphasized.     

Positioner and Clothing Artifact Can Affect One-Third Radius Bone Mineral Density Measurement

This report identifies a radius dual-energy X-ray absorptiometry (DXA) confounder and technical approach to avoid this inaccuracy. Initially, a precision study revealed substantial differences (p < 0.001) in radius bone mineral density (BMD) least significant change ranging from 0.038 to 0.073 g/cm² between 3 technologists that each performed assessments in 30 men and 30 women. Subsequently, visual examination of all 360 forearm DXA images, including bone, soft tissue, neutral, and air point-typing was performed. Errors in automated “soft tissue” identification were observed; compared with the manufacturer's ideal depiction, suboptimal soft tissue point-typing was present in 30/360 scans (8.3%) involving 27 individuals. These point-typing deviations appeared to result from inclusion of forearm positioner slots at the scan field edges or clothing covering the forearm. Twenty-four individuals had a paired scan appropriately point-typed, thus allowing evaluation of the effect on BMD measurement. In those with incorrect point-typing associated with positioner slots, the mean one-third radius BMD was ～7% higher. In conclusion, positioner slots at the edges of the distal scan field can lead to automated soft tissue identification inaccuracies and consequent erroneous one-third radius BMD measurement. DXA technologists should avoid slot inclusion in forearm scans and evaluate point-typing as part of routine analysis.     

Age-Related Changes of the Orbit and Midcheek and the Implications for Facial Rejuvenation

Background Aging of the midface is complex and poorly understood. Changes occur not only in the facial soft tissues, but also in the underlying bony structure. Computed tomography (CT) imaging was used for investigating characteristics of the bony orbit and the anterior wall of the maxilla in patients of different ages and genders. Methods Facial CT scans were performed for 62 patients ranging in age from 21 to 70 years, who were divided into three age groups: 21–30 years, 41–50 years, and 61–70 years. Patients also were grouped by gender. The lengths of the orbital roof and floor and the angle of the anterior wall of the maxilla were recorded on parasagittal images through the midline of the orbit for each patient. Results The lengths of the orbital roof and floor at their midpoints showed no significant differences between the age groups. When grouped by gender, the lengths were found to be statistically longer for males than for females. The angle between the anterior maxillary wall and the orbital floor was found to have a statistically significant decrease with advancing age among both sexes. Conclusion Bony changes occur in the skeleton of the midcheek with advancing age for both males and females. The anterior maxillary wall retrudes in relation to the bony orbit, which maintains a fixed anteroposterior dimension at its midpoint. These changes should be considered in addressing the aging midface.     

‘Making Concave Faces Convex’

Inadequate projection of the midface skeleton results in midface concavity. Patients with this skeletal morphology tend to have prominent eyes and noses. Lack of skeletal support for the midface soft tissue envelope predisposes to premature cheek descent, resulting in palpebral fissure distortion and lower lid “bags,” an appearance of early aging. Concave midfaces can be made convex with two basic maneuvers performed through intraoral and periorbital incisions. Midface skeletal projection can be increased by augmenting the facial skeleton with alloplastic implants. Multiple implants are required to replicate the complex curvature of the midface skeleton and to avoid impingement on the infraorbital nerve. Subperiosteal elevation of the midface soft tissues and repositioning provides cheek fullness and narrows the palpebral fissure while masking eyelid “bags.” The resultant midface concavity makes the eyes and nose appear less prominent. This procedure has been a safe and effective treatment for 14 patients treated over a 4-year period.Presented at the 17th Congress of the International Society of Aesthetic Plastic Surgery in Houston Texas, October, 2004     

The use of hydroxyapatite granules for the correction of skeletal facial deformities

Augmentation of the craniomaxillofacial region is required for many esthetic and reconstructive procedures. Although a variety of different materials and techniques have been described, coral-derived hydroxyapatite granules (HA), which are biocompatible with bone, seem to be the ideal material. In the past 25 years, we have observed HA granules to be a safe, stable, easy to use, and cost-effective material that can provide the exact shape and size of the area to be augmented. Complications are few, and the technique is simple and quick. This study is an update of our previous articles studying HA granules as an augmentation and reconstructive material. This material has been proven to be an effective tool in facial cosmetic and reconstructive surgery.     

Medium term outcomes of planovalgus foot correction in children using a lateral column lengthening approach with additional procedures ‘a la carte’

BackgroundWe report our medium term outcomes following surgery for symptomatic planovalgus malalignment in children. The technique we describe commences with lateral column lengthening and includes subsequent bony and soft tissue procedures which are carried out ‘a la carte’ in response to the underlying pathology and the behaviour of the foot to the lateral column lengthening.MethodsSurgery was undertaken on twenty five symptomatic planovalgus feet in 15 patients at a mean age of 12 years and 6 months (5 years 7 months to 16 years and 3 months). The case-mix was principally idiopathic pes planovalgus but included overcorrected club foot and skewfoot deformity. Following lateral column lengthening (using a tricortical interpositional os calcis bone graft) the ‘a la carte’ elements of the surgery undertaken included both bony and soft tissue elements: heel shift; medial cuneiform osteotomy with iliac crest tricortical bone grafting, peroneus brevis/peroneus longus transfer; plantar fascia release; tibialis posterior advancement. VAS FA and AOFAS scores, clinical findings and complications were recorded.ResultsTwelve patients (20 feet) were available for follow up at a mean of 4 years and 6 months years (2 years and 8 months to 6 years and 3 months). VAS FA and AOFAS scores were 82 ± 17 (50–99), 87 ± 14 (61–100) and 80 ± 10 (62–100), respectively. In all patients the reconstituted medial arch was maintained. Three patients (5 feet) required a second corrective procedure.ConclusionWe propose lateral column lengthening with additional ‘a la carte’ procedures in the surgical treatment of symptomatic pes planovalgus in childhood as a reliable corrective surgical procedure on the basis of favourable medium term functional outcomes.     

Errors in Dual-Energy X-Ray Scanning of the Hip Because of Nonuniform Fat Distribution

The variable proportion of fat in overlying soft tissue is a potential source of error in dual-energy X-ray absorptiometry (DXA) measurements of bone mineral. The effect on spine scanning has previously been assessed from cadaver studies and from computed tomography (CT) scans of soft tissue distribution. We have now applied the latter technique to DXA hip scanning. The CT scans performed for clinical purposes were used to derive mean adipose tissue thicknesses over bone and background areas for total hip and femoral neck. The former was always lower. More importantly, the fat thickness differences varied among subjects. Errors because of bone marrow fat were deduced from CT measurements of marrow thickness and assumed fat proportions of marrow. The effect of these differences on measured bone mineral density was deduced from phantom measurements of the bone equivalence of fat. Uncertainties of around 0.06 g/cm² are similar to those previously reported for spine scanning and the results from cadaver measurements. They should be considered in assessing the diagnostic accuracy of DXA scanning.     

Photographic Facial Soft Tissue Analysis of Healthy Turkish Young Adults: Anthropometric Measurements

Background  The purpose of this study was to establish facial soft tissue norms for Turkish young adults. Methods  Anthropometric measurements of the facial soft tissue were taken from 281 female and 149 male Turkish adults aged between 18 and 24 years. The soft tissue facial profiles were digitally analyzed using linear (17 vertical and 10 horizontal) measurements made with standardized photographic records, taken in a natural head position, to determine the average soft tissue facial profile for males and females. Results  A statistically significant difference was found between males and females in 20 of 27 measurements taken (p < 0.001). The most prominent differences between the sexes were observed in the measurements taken from the face region. Results were compared with other ethnic groups.     

Hydroxyapatite-coated acetabular components. Histological and histomorphometric analysis of six cups retrieved at autopsy between three and seven years after successful implantation.

BACKGROUND: Important questions remain regarding the use of hydroxyapatite-coated acetabular components in total hip arthroplasty. What is the relation of resorption of the hydroxyapatite coating to enduring fixation? Will unresorbed or dislodged hydroxyapatite particles cause adverse tissue reactions? Retrieval studies of clinically well-functioning acetabular components should help to answer these questions. METHODS: We examined six clinically successful hydroxyapatite-coated cementless acetabular components that were retrieved at autopsy between 3.3 and 6.6 years after implantation. All components were of the same design. The prostheses and the surrounding bone were prepared for qualitative histological and quantitative histomorphometric analysis. The percentage of bone growth onto the implant, the relative bone area around the implant, the extent of residual hydroxyapatite coating, and the coating thickness were measured. RESULTS: All of the cups showed bone ongrowth, with a mean bone-implant contact (and standard deviation) of 36.5% +/- 13.5%. The contact area was the same in all three zones delineated by DeLee and Charnley. The extent and thickness of the hydroxyapatite layer were much reduced in the specimens from older patients and in those associated with a longer duration of implantation. Degradation of the hydroxyapatite coating by osteoclasts was observed. We did not observe loose hydroxyapatite granules far from the coating, nor did we note any adverse tissue reaction to these granules. In contrast, polyethylene debris was noted in approximately half of the empty screw-holes. CONCLUSIONS: Cell-mediated hydroxyapatite resorption seems to be the main reason for loss of hydroxyapatite coating. The area of bone ongrowth was within a certain range (20% to 50%) of the measured surfaces, and it was independent of the amount of hydroxyapatite residue. The hydroxyapatite coating showed a slow rate of resorption with time, without any adverse tissue reactions.     

The role of facial skeletal augmentation and dental restoration in facial rejuvenation

Facial aging is almost exclusively a result of soft tissue changes in patients with full dentition. Loss of teeth can hasten facial aging and make aging more pronounced as a result of bony erosion of the alveolar ridges. This article describes these changes and demonstrates that properly selected oral implants and precisely placed hydroxyapatite implants can integrate with facelifts to produce superior facial rejuvenation in edentulous patients.     

Comparison of Hydroxyapatite Granules to Autogenous Bone Graft in Fusion Cages in a Goat Model

Background

With the increased use of fusion cages to achieve lumbar intervertebral fusion, the question arises as to the potential for bone ingrowth from the host bone through the entire cage. Is it even necessary to have an autogenous graft to achieve total bone incorporation?

Methods

Nine adult male goats had fusion cages implanted into three vertebral bodies. The design was Surgical Dynamics/Ray Fusion Cage, measuring 21 mm × 14 mm. In each animal, one fusion cage was filled with autogenous graft, one with hydroxyapatite, porous granules, and the other with nonporous granules. Amount of new bone formation was determined by backscatter electron microscopy at 3 months post implantation in all animals.

Results

The histologic section shows that there was total incorporation in all specimens at 3 months. There was slightly more new bone (43%) with the nonporous granules compared with the porous granules (35%). The amount of residual void space was about the same in all specimens, indicating that the amount of new bone formation was similar and not statistically different in cages filled with hydroxyapatite granules versus granules of autogenous bone.

Conclusion

This study confirms that total incorporation by ingrowth of new bone can be expected in fusion cages. The amount of ingrowth is about the same for autogenous graft versus hydroxyapatite granules. Apparently, it is not necessary to use bone graft to achieve successful bone incorporation if an acceptable biocompatable lattice, such as hydroxyapatite granules, is used.     

On-lay grafting of a calcium hydroxyapatite bone substitute: A preliminary animal experimental study

BackgroundBone substitutes are widely accepted for various clinical applications. However, the usage is predominantly intraosseous implantation, whereas extraosseous on-lay grafting is rare and lacks scientific evidence. The purpose of this study is to elucidate whether osteoconduction occurs in on-lay grafted bone substitute.MethodsCustom-made interconnected porous calcium hydroxyapatite ceramic (IPCHA) was on-lay grafted with screw or anchor fixation (S- and A-groups, respectively) at the anterior aspect of the femur of skeletally mature Japanese white rabbits. At 3, 6 and 12 weeks postoperatively, 4 samples for each time point and each group were evaluated by microfocus computed tomography (micro-CT) and histology.ResultsVolume-rendered three-dimensional micro-CT images showed a high-density calcified area infiltrating IPCHA from the femoral cortex as of 6 weeks. When quantified, the calcified volume per unit volume first showed no difference between the two groups at 3 weeks but increased over time, and became significantly greater in the S-group than in the A-group (p = 0.012 and 0.004 at 6 and 12 weeks, respectively). Histologically, IPCHA pores were first occupied by fibrous tissue at 3 weeks; then, the pores adjacent to the femoral cortex were gradually replaced by bony tissue as of 6 weeks for both fixations.ConclusionsIPCHA allowed new bone formation inside the material even though it was implanted in an on-lay fashion on the cortical bone. Our results suggested that on-lay grafted IPCHA exerted its osteoconductivity well, with more new bone forming in screw-fixated samples than in anchor-fixated samples.     

Habitual and Low-Impact Activities are Associated with Better Bone Outcomes and Lower Body Fat in Older Women

The influence of habitual and low-impact physical activity (PA) on bone health and soft tissue including bone-free lean (BFL) and fat mass is less elucidated than the influence of high-impact activities. This study examines the interactive effects of PA and soft tissue on bone mineral density (BMD) and content (BMC) in healthy Caucasian women, aged 68.6 ± 7.1 years, with body mass index (BMI) of 26.0 ± 3.8 kg/m² evaluated at baseline and every 6 months for 3 years. Measurements/assessments included BMD/BMC and soft tissue (by dual-energy X-ray absorptiometry), anthropometrics, dietary intake, and PA. Activities assessed were past activity, present heavy housework, gardening, do-it-yourself activities, stair-climbing, walking, walking pace, sports/recreation, and total activity. Baseline analyses revealed significant positive associations between past activity, heavy housework, faster-paced walking, BFL, and BMD/BMC of various skeletal sites. Prospective analyses showed subjects with more walking hours/week had significantly higher BMD/BMC of several skeletal sites (P < 0.05). Stratification by cumulative (over 3 years) median for heavy housework, walking, sports/recreational, and total activities revealed higher BMD and BMC in the femur and spine (P = 0.01) in subjects with those activities above median. Multivariate analysis of covariance results revealed that weight had the strongest influence on BMD and BMC, followed by BFL. Various modes of PA were negatively associated with BMI and fat but not with BFL. In conclusion, heavy housework, walking (faster pace), sports/recreational activities, and overall total participation in low-impact PA were beneficial for bone and for achieving more favorable body weight and fat but were not associated with BFL. The results indicate that even habitual activities engaged in by older women could benefit their bone and diminish body fat.     

Teriparatide in Bisphosphonate-Resistant Osteoporosis: Microarchitectural Changes and Clinical Results After 6 and 18 months

A number of osteoporotic patients under bisphosphonate treatment present persistent fragility fractures and bone loss despite good compliance. The objective of this 18-month prospective study was to investigate the effect of teriparatide [rhPTH(1–34)] in 25 female osteoporotics who were inadequate responders to oral bisphosphonates and to correlate microarchitectural changes in three consecutive iliac crest biopsies measured by micro-computed tomography (μCT) with bone mineral density (BMD) and bone serum markers. Scanned biopsies at baseline (M0), 6 months (M6), and 18 months (M18) demonstrated early significant (P < 0.01) increases in bone volume per tissue volume (+34%) and trabecular number (+14%) at M6 with only moderate changes in most μCT structural parameters between M6 and M18. μCT-measured bone tissue density was significantly decreased at M18, expressing an overall lower degree of tissue mineralization characteristic for new bone formation despite unchanged trabecular thickness due to increased intratrabecular tunneling at M18. μCT results were consistent with serum bone turnover markers, reaching maximal levels of bone alkaline phosphatase and serum β-crosslaps at M6, with subsequent decline until M18. BMD assessed by DXA demonstrated persistent increases at the lumbar spine until M12, whereas no significant change was observed at the hip. Type (alendronate/risedronate) and duration (3.5 ± 4 years) of prior bisphosphonate treatment did not influence outcome on μCT, BMD, or bone marker results. The overall results indicate a positive ceiling effect of teriparatide on bone microarchitecture and bone markers after 6 and 12 months for lumbar spine BMD, with no additional gain until M18 in bisphosphonate nonresponders.