The diagnostic accuracy of inflammatory blood markers for purulent flexor tenosynovitis.

PURPOSE: For patients with purulent flexor tenosynovitis, our purpose was to (1) calculate the diagnostic accuracy of white blood count (WBC), erythrocyte sedimentation rate (ESR), and C-reactive protein (CRP) for those who underwent surgical drainage, (2) to correlate these markers for those treated with antibiotics alone, and (3) to evaluate the accuracy of diagnosis for surgical patients. METHODS: A total of 82 consecutive patients (71 surgical and 11 nonsurgical) with flexor tenosynovitis were identified from orthopedic databases at 2 academic centers. We evaluated inflammatory markers (WBC, ESR, and CRP), radiographs, descriptions of surgical findings, and intraoperative cultures for all patients. For nonsurgical patients, we evaluated inflammatory markers for possible correlation with the presumed diagnosis of purulent flexor tenosynovitis. For surgical patients, sensitivity, specificity, positive predictive value, and negative predictive value were calculated individually for inflammatory markers. RESULTS: For nonsurgical patients, WBC, ESR, and CRP were elevated in 3 of 11 patients (27%), 6 of 8 patients (75%), and 6 of 7 patients (86%), respectively. For surgical patients, the intraoperative findings or cultures were consistent with infection in 69 of 71 cases (97%), whereas calcific tendinitis was diagnosed in 2 cases. Cultures were positive in 56 patients (79%). All 3 markers had a specificity and positive predictive value of 100%. For WBC, ESR, and CRP, respectively, the sensitivity was 39%, 41%, and 76% and the negative predictive value was 4%, 3%, and 13%. CONCLUSIONS: Commonly used inflammatory blood markers (WBC, ESR, and CRP) may be helpful in diagnosing purulent flexor tenosynovitis. If the levels of any of these markers are elevated in patients suspected of having the diagnosis, the likelihood of infection is extremely high. However, with low negative predictive values, these markers cannot reliably rule out infection. TYPE OF STUDY/LEVEL OF EVIDENCE: Diagnostic III.

Risk factors for complications of open trigger finger release.

BACKGROUND: Open trigger finger release is generally considered a simple low-risk procedure. Reported complication rates vary widely from 1 to 43 %, mostly based on small studies. Our goal was to determine the incidence of complications in a large consecutive series, while also identifying potential risk factors. METHODS: All open trigger finger releases performed from 2006 to 2009 by four fellowship-trained hand surgeons at a single institution were retrospectively reviewed. There were 795 digits released in 543 patients. Complications were defined as signs or symptoms requiring further treatment and/or considered unresolved by 1 month postoperatively. Complications requiring operative intervention were regarded as major. Multivariable analysis was performed to determine possible risk factors for complications. RESULTS: There were 95 documented complications among 795 digits (12 %). The most common complications involved persistent pain, stiffness, or swelling, persistent or recurrent triggering, or superficial infection. Most were treated nonoperatively with observation, therapy, steroid injection, or oral antibiotics. There were 19 reoperations (2.4 %), mostly including revision release, tenosynovectomy, and irrigation and debridement. Male gender, sedation, and general anesthesia were independently associated with complications, while age, diabetes, hypothyroidism, recent injection, and concurrent procedures were not associated. CONCLUSIONS: Open trigger finger release is generally a low-risk procedure, although there is potential for complications, some requiring reoperation. Male gender, sedation, and general anesthesia may be associated with greater risk. Surgeons should be careful to thoroughly discuss the risk of both major and minor complications when counseling patients.

Volar locking plate implant prominence and flexor tendon rupture.

BACKGROUND: Flexor tendon injury is a recognized complication of volar plate fixation of distal radial fractures. A suspected contributing factor is implant prominence at the watershed line, where the flexor tendons lie closest to the plate. METHODS: Two parallel series of patients who underwent volar locked plating of distal radial fractures from 2005 to 2008 and with at least six months of follow-up were retrospectively reviewed. Group 1 included seventy-three distal radial fractures that were treated by three orthopaedic hand surgeons with use of a single plate design at one institution, and Group 2 included ninety-five distal radial fractures that were treated by four orthopaedic hand surgeons with use of a different plate design at another institution. On the postoperative lateral radiographs, a line was drawn tangential to the most volar extent of the volar rim, parallel to the volar cortical bone of the radial shaft. Plates that did not extend volar to this line were recorded as Grade 0. Plates volar to the line, but proximal to the volar rim, were recorded as Grade 1. Plates directly on or distal to the volar rim were recorded as Grade 2. RESULTS: In Group 1, the average duration of follow-up was thirteen months (range, six to forty-nine months). Three cases of flexor tendon rupture were identified among seventy-three plated radii (prevalence, 4%). Grade-2 plate prominence was found in two of the three cases with rupture and in forty-six cases (63%) overall. In Group 2, the average duration of follow-up was fifteen months (range, six to fifty-six months). There were no cases of flexor tendon rupture and no plates with Grade-2 prominence among ninety-five plated radii. CONCLUSIONS: Flexor tendon rupture after volar plating of the distal part of the radius is an infrequent but serious complication. The plate used in Group 1 is prominent at the watershed line of the distal part of the radius, which may increase the risk of tendon injury. We found no ruptures in Group 2, perhaps as a result of the lower profile of the plate. Further studies are needed before recommending one plate over another. Regardless of plate selection, surgeons should avoid implant prominence in this area.

Bone marrow lesions from osteoarthritis knees are characterized by sclerotic bone that is less well mineralized.

INTRODUCTION: 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. METHODS: 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. RESULTS: 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. CONCLUSIONS: 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.

Combined effects of recombinant human BMP-7 (rhBMP-7) and parathyroid hormone (1-34) in metaphyseal bone healing.

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.

Current and future clinical applications of bone morphogenetic proteins in orthopaedic trauma surgery.

Forty years after the discovery by Marshal R. Urist of a substance in bone matrix that has inductive properties for the development of bone and cartilage, there are now 15 individual human bone morphogenetic proteins (BMPs) that possess varying degrees of inductive activities. Two of these, BMP-2 and BMP-7, have become the subject of extensive research aimed at developing therapeutic strategies for the restoration and treatment of skeletal conditions. This has led to three different therapeutic preparations, each for a distinct clinical application. Non-union, open tibial fractures and spinal fusions are the three conditions for which there is clinical approval for use of BMPs. This article reviews the evidence supporting the therapeutic applications of BMPs as they are presently available and suggests future applications based on current research. Among the future directions discussed are percutaneous injections, protein carriers, advances in gene transfer technology and the use of BMPs to engineer the regeneration of skeletal parts.