Morbidity of Nerve Transfers for Brachial Plexus Birth Injury: A Systematic Review.

BACKGROUND: The purpose of this article is to systematically review the peer-reviewed literature on the morbidity of nerve transfers performed in patients with brachial plexus birth injury (BPBI). Nerve transfers for restoration of function in patients with BPBI that fail nonoperative management are increasing in popularity. However, relatively little attention has been paid to the morbidity of these transfers in the growing patient. The authors systematically review the current literature regarding donor site morbidity following nerve transfer for BPBI. METHODS: A systematic review of the Medline and EMBASE databases was conducted through February 2020. Primary research articles written in English and reporting donor site morbidity after nerve transfer for BPBI were included for review. RESULTS: Thirty-six articles met inclusion criteria, all of which were retrospective reviews or case reports. There was great heterogeneity in outcomes assessed. With 5 year or less follow-up, all transfers were relatively well tolerated with the exception of the hypoglossal nerve transfer. CONCLUSION: Nerve transfers are a well-recognized treatment strategy for patients with BPBI and have an acceptable risk profile in the short term. Full hypoglossal nerve transfers for BPBI are of historical interest. Donor site morbidity is grossly underreported. This review highlights the need for more objective and systematic reporting of donor site outcomes, and the need for longer term follow-up in these patients. LEVEL OF EVIDENCE: Systematic review. Level III-therapeutic.

Surgical Technique: Closed Reduction and Percutaneous Pinning of Posterolaterally Displaced Supracondylar Humerus Fractures.

SUMMARY: Gartland type III posterolateral (IIIB) supracondylar humerus fractures are common among the pediatric population and can lead to concomitant injury, including compromise of the brachial artery and median nerve and long-term deformity, such as cubitus varus. These fractures can be difficult to reduce, and there is little consensus regarding the optimal technique for closed reduction and percutaneous pinning. Here, we discuss the management of Gartland III posterolateral supracondylar humerus fractures, including an in-depth technical description of the methods of operative fixation. We describe a lateral pin-only fixation technique for Gartland III posterolateral supracondylar humerus fractures that uses the intact periosteum during reduction of the distal fragment to assist in realigning the medial and lateral columns anatomically. We also discuss a safe method for placing a medial-based pin if there is persistent rotational instability at the fracture site after placement of the laterally based pins.

Internal Rotation Stress Testing Improves Radiographic Outcomes of Type 3 Supracondylar Humerus Fractures.

BACKGROUND: The purpose of this study was to determine if routine use of an intraoperative internal rotation stress test (IRST) for type 3 supracondylar humerus fractures will safely improve maintenance of reduction. METHODS: An intraoperative protocol for type 3 supracondylar humerus fractures was adopted at our institution, consisting of fracture reduction, placement of 2 laterally based divergent pins, and then an IRST to determine the need for additional fixation with a medial column pin placed through a small open approach. Fractures treated with the prospective IRST protocol were compared with a retrospective cohort before adoption of the protocol (pre-IRST). The primary outcomes were differences in Baumann's angle, lateral humerocapitellar angle, and the rotation index between final intraoperative fluoroscopic images and radiographs at final follow-up. Secondary outcomes were complications such as iatrogenic nerve injury, loss of fixation, or need for reoperation. RESULTS: There were 78 fractures in the retrospective cohort (pre-IRST) and 49 in the prospective cohort (IRST). Overall rotational loss of reduction (>6%), measured by lateral rotation percentage, and major rotational loss of reduction (>12%) were less common in the IRST cohort (6/49 vs. 27/78, P=0.007 overall; 0/49 vs. 8/78, P=0.02 major loss). There were no major losses of reduction for Baumann's angle (>12 degrees) in either cohort. There were 5 subjects in the pre-IRST cohort (6.4%) with a major loss of reduction of the humerocapitellar angle (>12 degrees) and none in the IRST cohort (P=0.16) Loss of proximal fixation with need for reoperation occurred in 3 fractures in the pre-IRST cohort, and none in the IRST cohort (P=0.28). There were no postoperative nerve injuries in either group. CONCLUSIONS: Intraoperative IRST after placement of 2 lateral pins assists with the decision for additional fixation in type 3 supracondylar humerus fractures. This method improved the final radiographic rotational alignment, and was safely performed using a mini-open approach for medial pin placement. LEVEL OF EVIDENCE: Level III-prospective cohort compared with a retrospective cohort.

Posttraumatic Proximal Radioulnar Synostosis after Closed Reduction for a Radial Neck and Olecranon Fracture.

Posttraumatic proximal radioulnar synostosis (PPRUS) is a severe complication of radial head and neck fractures known to occur after severe injury or operative fixation. Cases of PPRUS occurring after minimally displaced, nonoperatively treated radial neck injuries are, by contrast, extremely rare. Here, we present a pediatric case of PPRUS that developed after a nonoperatively treated minimally displaced radial neck fracture with concomitant olecranon fracture. While more cases are needed to establish the association between this pattern of injury and PPRUS, we recommend that when encountering patients with a minimally displaced radial neck fracture and a concomitant elbow injury, the rare possibility of developing proximal radioulnar synostosis should be considered.

Radiation Exposure During Operative Fixation of Pediatric Supracondylar Humerus Fractures: Is Lead Shielding Necessary?

BACKGROUND: Factors that impact radiation exposure during operative fixation of pediatric supracondylar humerus (SCH) fractures have been investigated; however, no studies have measured the equivalent dose at the patient's radiosensitive organs. Our hypothesis was that intraoperative fluoroscopy exposes pediatric patients to a significant radiation load and lead shielding of radiosensitive organs is important. The goal of the study was to quantify the patient's radiation exposure during the procedure by measuring the radiation load at the thyroid and gonads. METHODS: A prospective quality improvement project of radiation exposure during percutaneous fixation of isolated SCH fractures was performed over a 4-week period. The c-arm image intensifier was used as the operating table and radiation dosimeters were positioned over the thyroid and gonadal lead shields. Fluoroscopy times were recorded, doses were calculated, and the dosimeters were analyzed. To assure that the prospective cohort was representative of a larger population of SCH fractures, demographics and fluoroscopy time of the prospective cohort were compared with a 12-month retrospective cohort in which dosimetry was not performed. RESULTS: Prospective cohort-18 patients with type 2 (8) and type 3 (10) fractures were prospectively studied with intraoperative measurement of thyroid and gonadal radiation equivalent doses. Mean age was 4.9 years (1.9 to 9.5 y) and mean weight was 21.4 kg (13.1 to 33.5 kg). Mean fluoroscopy time was 65.0 seconds (25.3 to 168.4 s), and absorbed skin dose at the elbow was 0.47 mGy (0.18 to 1.21 mGy). The radiation dosimeters overlying the thyroid and gonads measured minimal radiation indicating equivalent doses of <0.01 mSv for all patients in the prospective cohort.Retrospective cohort-163 patients with type 2 (60) and type 3 (103) fractures were retrospectively studied. The mean age was 5.5 years (0.02 to 13.7 y) and weight was 21.6 kg (2.0 to 71.9 kg). Mean fluoroscopy time was 74.1 seconds (10.2 to 288.9 s), and absorbed skin dose at the elbow was 0.53 mGy (0.07 to 2.07 mGy).There were no statistically significant differences between the cohorts. CONCLUSIONS: The smaller prospective cohort had fluoroscopy times and radiation doses that were not statistically different from the larger retrospective cohort, suggesting that the dosimeter measurements are representative of intraoperative radiation exposure during fixation of pediatric SCH fractures. The equivalent dose to the thyroid and gonads was minimal and approximates daily background radiation. Shielding of radiosensitive organs is appropriate when practical to minimize cumulative lifetime radiation exposure, particularly in smaller patients and when longer fluoroscopy times are anticipated. LEVEL OF EVIDENCE: Level 2.

Radial to axillary nerve neurotization for brachial plexus injury in children: a combined case series.

OBJECT: Axillary nerve palsy, isolated or as part of a more complex brachial plexus injury, can have profound effects on upper-extremity function. Radial to axillary nerve neurotization is a useful technique for regaining shoulder abduction with little compromise of other neurological function. A combined experience of this procedure used in children is reviewed. METHODS: A retrospective review of the authors' experience across 3 tertiary care centers with brachial plexus and peripheral nerve injury in children (younger than 18 years) revealed 7 cases involving patients with axillary nerve injury as part of an overall brachial plexus injury with persistent shoulder abduction deficits. Two surgical approaches to the region were used. RESULTS: Four infants (ages 0.6, 0.8, 0.8, and 0.6 years) and 3 older children (ages 8, 15, and 17 years) underwent surgical intervention. No patient had significant shoulder abduction past 15° preoperatively. In 3 cases, additional neurotization was performed in conjunction with the procedure of interest. Two surgical approaches were used: posterior and transaxillary. All patients displayed improvement in shoulder abduction. All were able to activate their deltoid muscle to raise their arm against gravity and 4 of 7 were able to abduct against resistance. The median duration of follow-up was 15 months (range 8 months to 5.9 years). CONCLUSIONS: Radial to axillary nerve neurotization improved shoulder abduction in this series of patients treated at 3 institutions. While rarely used in children, this neurotization procedure is an excellent option to restore deltoid function in children with brachial plexus injury due to birth or accidental trauma.

The temporal and spatial development of vascularity in a healing displaced fracture.

Underlying vascular disease is an important pathophysiologic factor shared among many co-morbid conditions associated with poor fracture healing, such as diabetes, obesity, and age. Determining the temporal and spatial patterns of revascularization following a fracture is essential for devising therapeutic strategies to augment this critical reparative process. Seminal studies conducted in the last century have investigated the pattern of vascularity in bone following a fracture. The consensus model culminating from these classical studies depicts a combination of angiogenesis emanating from both the intact intramedullary and periosteal vasculature. Subsequent to the plethora of experimental fracture angiography in the early to mid-20th century there has been a paucity of reports describing the pattern of revascularization of a healing fracture. Consequently the classical model of revascularization of a displaced fracture has remained largely unchanged. Here, we have overcome the limitations of animal fracture models performed in the above described classical studies by combining novel techniques of bone angiography and a reproducible murine femur fracture model to demonstrate for the first time the complete temporal and spatial pattern of revascularization in a displaced/stabilized fracture. These studies were designed specifically to i) validate the classical model of fracture revascularization of a displaced/stabilized fracture, ii) assess the association between intramedullary and periosteal angiogenesis and iii) elucidate the expression of VEGF/VEGF-R in relation to the classical model. From the studies, in conjunction with classic studies of angiogenesis during fracture repair, we propose a novel model (see abstract graphic) that defines the process of bone revascularization subsequent to injury to guide future approaches to enhance fracture healing. This new model validates and advances the classical model by providing evidence that during the process of revascularization of a displaced fracture 1) periosteal angiogenesis occurs in direct communication with the remaining intact intramedullary vasculature as a result of a vascular shunt and 2) vascular union occurs through an intricate interplay between intramembranous and endochondral VEGF/VEGF-R mediated angiogenesis.

Epidemiology, diagnosis, and treatment of pericapsular pyomyositis of the hip in children.

BACKGROUND: The yield of synovial fluid cultures in patients meeting clinical criteria for septic hip arthritis remains low. In the presence of positive blood cultures, these patients are diagnosed and treated as "presumed septic arthritis." We hypothesized that some of these patients may instead have an extra-articular infection, such as pericapsular pyomyositis. METHODS: An IRB-approved prospective study of children with suspected septic hip arthritis at a tertiary care children's hospital over a 2-year time period was conducted. Children were evaluated with a previously published clinical algorithm with the addition of magnetic resonance imaging (MRI). RESULTS: Of the 53 patients presenting with an acutely irritable hip, 32% were found to have pericapsular pyomyositis, whereas 15% were diagnosed with septic arthritis. Although C-reactive protein (CRP, ≥33.1 mg/L) performed well at predicting infection, there were no significant differences in CRP, erythrocyte sedimentation rate, white blood cell count, temperature, or weight-bearing status in children with septic arthritis compared with pericapsular pyomyositis. In addition to MRI, there was a difference in the size of hip effusion on ultrasound, which was significantly smaller in cases of pericapsular pyomyositis. CRP (≥74.3 mg/L) was found to be predictive of need for surgical intervention in children with pericapsular pyomyositis. CONCLUSIONS: Correct anatomic diagnosis of the site of infection is essential for the efficient care of the child. Herein, we found that pericapsular pyomyositis is twice as common as septic arthritis in children presenting with an acutely irritable hip. Clinical algorithms are incapable of differentiating these pathologies suggesting that both be considered under the current diagnosis previously referred to as "presumed septic arthritis." Incorrect diagnosis of a septic arthritis in the presence of a pericapsular pyomyositis could potentially lead to unnecessary debridement of the joint in the presence of extra-articular infection, thus contaminating the joint. Conversely, debriding the joint instead of the epicenter of the infection can prolong the infectious process. For these reasons, we conclude that MRI has the potential to improve the clinical care of children by providing a more precise diagnosis. LEVEL OF EVIDENCE: Level II-"Diagnostic" [Development of diagnostic criteria on the basis of consecutive patients (with universally applied reference "gold" standard)].

Medial approach for drainage of the obturator musculature in children.

BACKGROUND: In a recent study designed to determine the anatomic location of infection in children presenting with acute hip pain, fever, and elevated inflammatory markers, we demonstrated the incidence of infection of the musculature surrounding the hip to be greater than twice that of septic arthritis. Importantly, the obturator musculature was infected in >60% of cases. Situated deep in the pelvis, surrounding the obturator foramen, debridement of these muscles and placement of a drain traditionally requires an extensive ilioinguinal or Pfannenstiel approach, placing significant risk to the surrounding neurovascular structures. We hypothesized that the obturator internus and externus could be successfully debrided using a limited medial approach. METHODS: An IRB-approved prospective study of children (0 to 18 y) evaluated in the pediatric emergency department by an orthopaedic surgeon to rule out septic hip arthritis at a tertiary care children's hospital (July 1, 2010 to June 30, 2012) was conducted. Infected obturator musculature was identified and confirmed using magnetic resonance imaging. Cadaveric dissection was performed comparing the ilioinguinal, Pfannenstiel, and proposed minimally invasive medial approach. The proposed approach was utilized to debride and place drains in 7 consecutive patients. RESULTS: Anatomic information gained from magnetic resonance images of patients with abscess within the obturator musculature, and from the results of cadaveric studies, allowed for planning of a novel surgical approach. We found that through the surgical approach used to perform an osteotomy of the ischium (Tonnis) the obturator externus could be debrided through the adductor brevis and the obturator internus could be debrided through the obturator foramen. Using our medial approach, resolution of symptoms in all children who underwent surgical drainage resulted without complication. CONCLUSIONS: Our medial approach can safely access the obturator musculature for abscess decompression and drain placement with successful results. Advantages to this approach include: lower risk to neurovascular structures within the pelvis, less soft tissue trauma, and similarity to current techniques used for adductor lengthening, medial reduction of the dislocated hip, and osteotomy of the ischium. LEVEL OF EVIDENCE: Level II.

Coagulopathies in orthopaedics: links to inflammation and the potential of individualizing treatment strategies.

Orthopaedic patients are at risk for developing pathologic imbalances of coagulation factors characterized by phases of both hypocoagulability and hypercoagulability. Complications from "hypocoagulability" include life-threatening hemorrhage, wound hematoma, and poor wound healing. Complications due to "hypercoagulability" include deep venous thrombosis, pulmonary embolus, and disseminated intravascular coagulation. In addition, coagulation imbalance that favors the production of procoagulant factors may lead to excessive inflammation and contribute to systemic inflammatory response syndrome, acute respiratory distress syndrome, multiple organ dysfunction syndrome, and death. Optimally, the goal of individualized treatment of coagulopathies in orthopaedic patients should be to achieve efficient healing while avoiding the morbidities associated with imbalance of coagulation and inflammation. Such individualized and time-sensitive measures of coagulation status require rapid, accurate, qualitative, and quantitative assessment of the critical balance of the coagulation system. Commonly used coagulation tests (prothrombin time and activated partial thromboplastin time) are incapable of determining this balance. An alternative to is to perform thrombin generation assays. The greatest advantage of thrombin generation assays over traditional coagulation tests is their ability to detect hypercoagulability, the balance of procoagulant and anticoagulant factors, and the effect of all pharmaceutical anticoagulants. Further clinical investigations are warranted to develop and refine the thrombin generation assays to help predict clinical complications related to coagulation imbalances. In addition, future testing will help define the prothrombotic period allowing for appropriate initiation and cessation of anticoagulant pharmaceuticals. These subsequent studies have the potential to allow the development of a real-time coagulation monitoring strategy that could have paramount implications in the management of postoperative patients.

Complex syndactyly: aesthetic and objective outcomes.

PURPOSE: Outcome data after the treatment of complex syndactyly are lacking. The purpose of this investigation was to critically analyze and report our results after surgical reconstruction of complex syndactyly. METHODS: We included 13 patients and 21 hands (25 webspaces) in this retrospective call-back investigation. There were 17 middle/ring finger and 8 ring/little finger complex syndactylies, each with a defined, isolated osseous bridge between the distal phalanges. We excluded complicated and syndrome-associated syndactylies. Patients returned for clinical examination and subjective assessment at an average of 9 years (range, 2-27 y) after the most recent surgery. Of 21 hands, 6 had undergone a revision surgery. RESULTS: The Vancouver Scar Scale scores averaged 3 (range, 0-6), web creep averaged 1.5 (range, 0-3), and total active motion averaged 148° for the affected fingers. In the middle/ring finger syndactylies, the middle finger was most commonly supinated (average, 13°) and ulnarly deviated (average, 9°), and the ring finger was either supinated or pronated and radially deviated (average, 13°). In the ring/little finger syndactylies, the ring finger was most commonly supinated (average, 8°) without deviation, and the little finger was most commonly pronated (average, 8°) and radially deviated (average, 24°). There was a notable nail wall deformity in most fingers. Surgeon visual analog scale scores (range, 0-10, where lower scores are better) averaged 2.8 (range, 0.8-5.0). Patient visual analog scale scores were 0.4 (range, 0-3) for pain, 1.9 (range, 0-10) for appearance, and 1.1 (range, 0-3) for function. CONCLUSIONS: Complex syndactyly reconstruction is challenging, and common postsurgical findings include rotational and angular deformity and nail deformity. When deformity was present, the fingers typically rotated away from and deviated toward the site of the previous complex syndactyly. We describe how we have altered our approach based on these findings. TYPE OF STUDY/LEVEL OF EVIDENCE: Therapeutic IV.

Supraclavicular nerve entrapment and clavicular fracture.

Because the supraclavicular nerve lies in close proximity to the clavicle, it is particularly vulnerable to injury in cases of clavicle fracture and in the surgical treatment of these fractures. The development of painful neuromas after iatrogenic transsection and symptomatic nerve entrapment in fracture callus after healing have previously been described. Reported here is a case of acute supraclavicular nerve entrapment and tension after fracture of the clavicle with significant pain relief after fracture fixation and nerve decompression.

Surgical and nonsurgical treatment of cubital tunnel syndrome in pediatric and adolescent patients.

PURPOSE: Few studies have investigated the presence or treatment of cubital tunnel syndrome in pediatric or adolescent patients. We conducted this retrospective investigation to quantify success rates of nonsurgical care and to assess patient outcomes after surgical intervention. METHODS: We identified 39 extremities treated for cubital tunnel syndrome between 2000 and 2009 at one institution. We documented patient demographic data, precipitating events, symptomatology, physical examination findings, and treatment for all patients. We assessed patient-rated outcomes with validated measures including the Disabilities of the Arm, Shoulder, and Hand (DASH) questionnaire and the visual analog scale (VAS). RESULTS: Subjective complaints at the time of presentation included 16 extremities with ulnar nerve instability at the elbow, 21 extremities with pain at the elbow, and 15 extremities with numbness and tingling in the ring and small fingers. Physical examination revealed 33 extremities with a positive Tinel sign and 20 extremities with a positive elbow flexion-compression test. In the nonsurgical group (9), pretreatment DASH scores averaged 32 and posttreatment DASH scores averaged 11. Pretreatment recall VAS pain scores had a median of 7, and were similar to posttreatment scores, which had a median of 3. In the surgical group (30), DASH scores averaged 46 before surgery and improved to 7 at final follow-up. The VAS pain scores improved from a median of 8 before surgery to 2 after surgery. A total of 30 patients (from both groups) were treated with a trial of nonsurgical care without symptom resolution. CONCLUSIONS: Cubital tunnel syndrome in pediatric or adolescent patients is rare. It can be treated successfully with surgical intervention. Although nonsurgical treatment is unlikely to relieve symptoms in this patient population, a trial of nighttime splinting, activity modification, and anti-inflammatory medications remains appropriate for most patients. Surgical intervention is effective for symptom relief if nonsurgical care fails. TYPE OF STUDY/LEVEL OF EVIDENCE: Therapeutic III.

Micro-computed tomography assessment of the progression of fracture healing in mice.

The mouse fracture model is ideal for research into the pathways of healing because of the availability of genetic and transgenic mice and the ability to create cell-specific genetic mutations. While biomechanical tests and histology are available to assess callus integrity and tissue differentiation, respectively, micro-computed tomography (µCT) analysis has increasingly been utilized in fracture studies because it is non-destructive and provides descriptions of the structural and compositional properties of the callus. However, the dynamic changes of µCT properties that occur during healing are not well defined. Thus, the purpose of this study was to determine which µCT properties change with the progression of fracture repair and converge to values similar to unfractured bone in the mouse femur fracture model. A unilateral femur fracture was performed in C57BL/6 mice and intramedullary fixation performed. Fractured and un-fractured contralateral specimens were harvested from groups of mice between 2 and 12 weeks post-fracture. Parameters describing callus based on µCT were obtained, including polar moment of inertia (J), bending moment of inertia (I), total volume (TV), tissue mineral density (TMD), total bone volume fraction (BV/TV), and volumetric bone mineral density (vBMD). For comparison, plain radiographs were used to measure the callus diameter (D) and area (A); and biomechanical properties were evaluated using either three-point bending or torsion. The µCT parameters J, I, TV, and TMD converged toward their respective values of the un-fractured femurs over time, although significant differences existed between the two sides at every time point evaluated (p<0.05). Radiograph measurement D changed with repair progression in similar manner to TV. In contrast, BV/TV and BMD increased and decreased over time with statistical differences between callus and un-fractured bone occurring sporadically. Similarly, none of the biomechanical properties were found to distinguish consistently between the fractured and un-fractured femur. Micro-CT parameters assessing callus structure and size (J, I, and TV) were more sensitive to changes in callus over time post-fracture than those assessing callus substance (TMD, BV/TV, and BMD). Sample size estimates based on these results indicate that utilization of µCT requires fewer animals than biomechanics and thus is more practical for evaluating the healing femur in the mouse fracture model.

Fracture healing in protease-activated receptor-2 deficient mice.

Protease-activated receptor-2 (PAR-2) provides an important link between extracellular proteases and the cellular initiation of inflammatory responses. The effect of PAR-2 on fracture healing is unknown. This study investigates the in vivo effect of PAR-2 deletion on fracture healing by assessing differences between wild-type (PAR-2(+/+)) and knock-out (PAR-2(-/-)) mice. Unilateral mid-shaft femur fractures were created in 34 PAR-2(+/+) and 28 PAR-2(-/-) mice after intramedullary fixation. Histologic assessments were made at 1, 2, and 4 weeks post-fracture (wpf), and radiographic (plain radiographs, micro-computed tomography (µCT)) and biomechanical (torsion testing) assessments were made at 7 and 10 wpf. Both the fractured and un-fractured contralateral femur specimens were evaluated. Polar moment of inertia (pMOI), tissue mineral density (TMD), bone volume fraction (BV/TV) were determined from µCT images, and callus diameter was determined from plain radiographs. Statistically significant differences in callus morphology as assessed by µCT were found between PAR-2(-/-) and PAR-2(+/+) mice at both 7 and 10 wpf. However, no significant histologic, plain radiographic, or biomechanical differences were found between the genotypes. The loss of PAR-2 was found to alter callus morphology as assessed by µCT but was not found to otherwise effect fracture healing in young mice.

2010 Young Investigator Award winner: Therapeutic aprotinin stimulates osteoblast proliferation but inhibits differentiation and bone matrix mineralization.

STUDY DESIGN: Analysis of the effect of antifibrinolytics on in vitro bone formation. OBJECTIVE: As the direct effect of antifibrinolytics on bone formation is unknown, we examined whether antifibrinolytics routinely used in spine surgery, namely, aprotinin and aminocaproic acid, affect osteoblast function in vitro. SUMMARY OF BACKGROUND DATA: Antifibrinolytics are used in spine surgery to prevent intraoperative blood loss and decrease the need for transfusion. They are either delivered systemically or included as a component of most tissue sealants. Although the role of the fibrinolytic system in wound healing is well established, reports of indirect effects on normal bone biology are emerging. This suggests that the pharmacological targeting of this system may also influence skeletal mass and integrity. METHODS: Osteoblast progenitor cells were cultured with therapeutic doses of aprotinin and aminocaproic acid. The effect of the antifibrinolytics on osteoblast development was determined by measuring cellular viability and proliferation, quantification of matrix mineralization, and genetic analysis of osteoblast differentiation markers. Protease inhibition profiles of the antifibrinolytics were determined by amidolytic chromogenic assays. RESULTS: Therapeutic concentrations of aprotinin dose-dependently inhibited plasmin's proteolytic activity, stimulated osteoblast proliferation, and inhibited osteoblast differentiation and matrix mineralization. Aprotinin inhibition of osteoblast differentiation and matrix mineralization could be recovered by removing aprotinin from culture or stimulating cells with bone morphogenetic protein-2 or plasmin. Conversely, aminocaproic acid inhibited plasmin's proteolytic activity significantly less than aprotinin and had no effect on osteoblast proliferation, differentiation, or matrix mineralization in its therapeutic range. CONCLUSION: These findings demonstrate that the antifibrinolytics have drastically different effects on osteoblasts due in part to different efficacies of protease inhibition. Further, this work suggests that the fibrinolytic proteases and their inhibitors have great potential to regulate bone by affecting the processes that control osteoblast growth and differentiation.

A prospective plan to minimise median nerve related complications associated with operatively treated distal radius fractures.

Loss of median nerve function or a neuropathic pain syndrome may occur in around 20% of distal radius fractures if post-traumatic oedema in the carpal canal generates excessive pressure on the median nerve. No method currently exists to reliably distinguish which patients may benefit from a concomitant carpal tunnel release. This case series details the results of following a prospective plan designed to minimise median nerve related complications associated with distal radius fractures by measuring Semmes-Weinstein monofilament scores in 374 radius fracture patients who underwent surgical stabilisation. One hundred and sixty-nine patients with the clinical symptoms of median nerve compression, a decrement in monofilament score of grade 1 (out of 5) compared to the contralateral side or at least 4.31 g underwent concomitant carpal tunnel release. The remaining 205 patients did not have carpal tunnel release. There were no cases of neuropathic pain or loss of median nerve function.

A unified approach to radial tunnel syndrome and lateral tendinosis.

Two of the most common diagnoses assigned to patients presenting with lateral elbow and proximal forearm pain are lateral tendinosis and radial tunnel syndrome. Traditionally, these 2 conditions have been treated as distinct and separate entities with most patients being diagnosed with either one or the other, but not both. The extensor carpi radialis brevis (ECRB) and, to a lesser the degree, a portion of the extensor digitorum communis that form the conjoined lateral extensor tendon are thought to be primarily responsible for the excessive traction that induces lateral tendinosis (a degenerative process of microtears in the tendon with impaired healing), but the supinator blends with these same fibers and shares a role in the pathology. The supinator, primarily the arcade of Frohse, has been thought to play the majority role in compressing the posterior interosseous nerve in radial tunnel syndrome, but the undersurface thick tendon of the ECRB may also cause substantial nerve compression. Reduction of the linear tension transmitted by the ECRB is the common element in the various surgical treatments for lateral tendinosis, performed anywhere from directly at the lateral epicondyle to the distal myotendinous junction. Nerve decompression by division of fascial bands is the goal in surgery for radial tunnel syndrome. These 2 surgical approaches need not be mutually exclusive. In fact, this separation of the 2 clinical entities may play a role in the unpredictable results reported in the literature. This article presents a unified approach to treating both pathologies simultaneously including short-term clinical results.