A David Davis

Boston Medical Center, Boston, Massachusetts, United States

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Publications (4)17.61 Total impact

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    ABSTRACT: Although the presence of bone marrow lesions (BMLs) on magnetic resonance images is strongly associated with osteoarthritis progression and pain, the underlying pathology is not well established. The aim of the present study was to evaluate the architecture of subchondral bone in regions with and without BMLs from the same individual using bone histomorphometry. Postmenopausal female subjects (n = 6, age 48 to 90 years) with predominantly medial compartment osteoarthritis and on a waiting list for total knee replacement were recruited. To identify the location of the BMLs, subjects had a magnetic resonance imaging scan performed on their study knee prior to total knee replacement using a GE 1.5 T scanner with a dedicated extremity coil. An axial map of the tibial plateau was made, delineating the precise location of the BML. After surgical removal of the tibial plateau, the BML was localized using the axial map from the magnetic resonance image and the lesion excised along with a comparably sized bone specimen adjacent to the BML and from the contralateral compartment without a BML. Cores were imaged via microcomputed tomography, and the bone volume fraction and tissue mineral density were calculated for each core. In addition, the thickness of the subchondral plate was measured, and the following quantitative metrics of trabecular structure were calculated for the subchondral trabecular bone in each core: trabecular number, thickness, and spacing, structure model index, connectivity density, and degree of anisotropy. We computed the mean and standard deviation for each parameter, and the unaffected bone from the medial tibial plateau and the bone from the lateral tibial plateau were compared with the affected BML region in the medial tibial plateau. Cores from the lesion area displayed increased bone volume fraction but reduced tissue mineral density. The samples from the subchondral trabecular lesion area exhibited increased trabecular thickness and were also markedly more plate-like than the bone in the other three locations, as evidenced by the lower value of the structural model index. Other differences in structure that were noted were increased trabecular spacing and a trend towards decreased trabecular number in the cores from the medial location as compared with the contralateral location. Our preliminary data localize specific changes in bone mineralization, remodeling and defects within BMLs features that are adjacent to the subchondral plate. These BMLs appear to be sclerotic compared with unaffected regions from the same individual based on the increased bone volume fraction and increased trabecular thickness. The mineral density in these lesions, however, is reduced and may render this area to be mechanically compromised, and thus susceptible to attrition.
    Arthritis research & therapy 02/2009; 11(1):R11. DOI:10.1186/ar2601 · 3.75 Impact Factor
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    ABSTRACT: To address persisting controversy in the literature concerning the efficacy of arthroscopic compared to open acromioplasty, a meta-analysis was performed to evaluate the treatment effect after both approaches. The final clinical outcomes will be the same after both open and arthroscopic acromioplasty. However, the arthroscopic technique results in faster recovery and less postoperative morbidity as reflected by faster return to work and decreased hospital stays. Meta-analysis; Level of evidence, 3. We performed our search of published English language literature using PubMed. We also searched the proceedings from 4 major orthopaedic meetings convened from 2000 to 2007. Furthermore, the reference sections of all relevant articles were reviewed for pertinent studies and presentations. Nine studies met the inclusion criteria that directly compared arthroscopic versus open acromioplasty with minimum follow-up of 1 year. The analysis focused on 1-year clinical outcome and included comparison of the objective 100-point score, hospital stay, time until return to work, operative time, and complications. No significant differences were found in clinical outcomes or complications for the 2 groups. However, open acromioplasty was associated with longer hospital stays (2.3 days, P = .05) and a greater length in time until return to work (65.1 days) compared with the arthroscopic technique (48.6 days) (P < .05). Arthroscopic and open acromioplasty have equivalent ultimate clinical outcomes, operative times, and low complication rates. However, arthroscopic acromioplasty results in faster return to work and fewer hospital inpatient days compared with the open technique.
    The American Journal of Sports Medicine 02/2009; 38(3):613-8. DOI:10.1177/0363546508328100 · 4.70 Impact Factor
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    ABSTRACT: Controversy remains regarding the results of all arthroscopic rotator cuff repairs compared with the mini-open approach. The purpose of this study was to perform a comprehensive literature search and meta-analysis of clinical trials comparing the results of arthroscopic rotator cuff repairs and mini-open rotator cuff repairs. There is no difference between the clinical results obtained from all arthroscopic rotator cuff repairs compared with mini-open repairs. Meta-analysis. A computerized search of articles published between 1966 and July 2006 was performed using MEDLINE and PubMed. Additionally, a search of abstracts from 4 major annual meetings each held between 2000 and 2005 was performed to identify Level I to III studies comparing the results of arthroscopic rotator cuff repair and mini-open repair. Studies that included follow-up of an average of over 2 years and a minimum of 1 year and included the use of 1 of 4 validated functional outcome scores used to study shoulder injuries were included in the present meta-analysis. All outcome scores were converted to a 100-point scale to allow for outcome comparison. Five studies that met the inclusion criteria were identified. There was no difference in functional outcome scores or complications between the arthroscopic and mini-open repair groups. Based on current literature, there was no difference in outcomes between the arthroscopic and mini-open rotator cuff repair techniques.
    The American Journal of Sports Medicine 10/2008; 36(9):1824-8. DOI:10.1177/0363546508322903 · 4.70 Impact Factor
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    ABSTRACT: Fracture healing involves multiple stages of repair and coordinated actions of multiple cell types. Consequently, it may be possible to enhance healing through treatment strategies that target more than one repair process or cell type. The goal of this study was to determine the combined effects of recombinant human bone morphogenetic protein 7 (rhBMP-7) and parathyroid hormone (PTH(1-34)) on metaphyseal bone healing. A wedge-shaped defect was created in the lateral aspect of the distal tibia in female New Zealand white rabbits (n=64) and was filled with tricalcium phosphate (TCP). Animals were assigned to four groups: 1) BMP-7 and PTH; 2) BMP-7; 3) PTH; and 4) control (TCP alone). In groups 1 and 2, 200 microg rhBMP-7 was incorporated into the TCP. Animals received daily subcutaneous injections of 10 microg/kg PTH(1-34) (groups 1 and 3) or saline (groups 2 and 4). Healing at 4 weeks was assessed using micro-computed tomography, histology, immunohistochemistry, and mechanical testing. Combined treatment with rhBMP-7 and PTH resulted in increased callus total volume (TV), mineralized volume (BV), average cross-sectional area, and bone mineral content (BMC) as compared to the control group (p<0.02). BV and BMC were also higher in the combined treatment group as compared to the BMP-7 group (p<0.02); however, tissue mineral density was highest in the BMP-7 group (p=0.002). New bone formation in the BMP-7 group was largely restricted to the defect site, while PTH promoted bone formation throughout the defect and surrounding regions. Combined treatment led to greater quantities of woven trabecular bone, increased trabecular thickness, decreased trabecular separation (p<0.04), and a trend towards increased numbers of osteoclasts (p=0.09). Combined treatment also resulted in increased torsional rigidity and compressive strength as compared to the control and BMP-7 groups (p<0.001). These results suggest that the improvements in mechanical function obtained with the combined treatment resulted from differing biological activities of rhBMP-7 and PTH. While the activities of rhBMP-7 appeared to be strictly anabolic, those of PTH appeared to work in the context of coupled remodeling. The combination of both agents led to greater bone volume as well as better microstructural organization and integration of this bone with the surrounding tissues.
    Bone 09/2008; 43(6):1031-8. DOI:10.1016/j.bone.2008.07.251 · 4.46 Impact Factor