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Mohit Bhandari

Publications and source records attributed to Mohit Bhandari.

At least 127 records · Page 7Linked to original sources
PubMed2002

Humeral shaft fractures as predictors of intra-abdominal injury in motor vehicle collision victims.

To assess the utility of humeral shaft fractures as predictors of organ injuries and skeletal injuries in multiply injured patients involved in motor vehicle collisions (MVCs). A prospectively collected database of multiply injured motor vehicle occupants with an Injury Severity Score (ISS) greater than 12 admitted to a level I regional trauma centre during a 102-month period (January 1992 to June 2000) was reviewed to assess skeletal and organ injuries associated with a humeral shaft fracture. The effect of occupant location within the vehicle, the point of collision, and the use of a seat belt restraint was also examined to identify trends in injury patterns. Data from 1070 motor vehicle occupants - 65 with concomitant humeral shaft fractures and 1005 without humeral shaft fractures - revealed that 63% of motor vehicle occupants who sustained humeral fractures were drivers, compared with 77% in the non-humeral fracture group. Those patients who sustained a humeral shaft fracture had a significantly greater number of liver injuries (p = 0.022), forearm/hand fractures (p < 0.001), tibial fractures (p < 0.01) and femoral fractures (p < 0.01) compared with controls. A lateral collision impact showed a trend towards increased splenic and hepatic injuries within the humeral shaft fracture group. The presence of a humeral shaft fracture in a multiply injured patient involved in a MVC is significantly associated with an increased incidence of both upper and lower extremity fractures and liver injury. Moreover, humeral shaft fractures may serve as a predictor of potential intra-abdominal pathology in multiply injured trauma patients involved in MVCs.

Abdominal Injuries↗
PubMed2002

In the dark: the reporting of blinding status in randomized controlled trials.

To determine the quality of reporting of blinding in randomized controlled trials (RCTs), we evaluated 40 consecutive RCTs published in each of five leading journals. We noted whether authors reported the blinding status of participants, health care providers, data collectors, judicial assessors of outcomes, data analysts, and manuscript writers. Explicit reporting of blinding status occurred in <25% of RCTs for all groups. Eighty-three RCTs, reported as double-blind, provided eight combinations of blinded groups. In conclusion, prestigious journals do not currently report blinding status optimally. To do so, journals should abandon the term "double blind" and explicitly report the blinding status of the groups involved in RCTs. Until such reporting occurs, clinicians will be left with uncertainty about the validity of RCTs that guide their clinical practice.

Bias↗
PubMed2002

Treatment of acute Achilles tendon ruptures: a systematic overview and metaanalysis.

A quantitative systematic review of randomized and quasirandomized trials was conducted to determine the effect of surgical versus conservative treatment of acute Achilles tendon ruptures on rates of rerupture. Secondary outcomes included deep infection rates, return to normal function, and minor complaints. A search of computerized databases was conducted to locate clinical studies published from 1969 to 2000. Additional studies were located through hand searches of major orthopaedic journals, bibliographies of major orthopaedic texts, and personal files. Of the 273 citations initially identified, 11 proved potentially eligible, and six met all eligibility criteria. Three investigators independently graded study quality and abstracted relevant data. Among the studies, surgical repair revealed a significant reduction in the risk of rerupture when compared with conservative treatment. Alternatively, the risk of infection with surgical repair was significantly increased. Pooled analysis of studies did not reveal any difference in the risk of minor complaints or return to normal function between surgical repair and conservatively treated groups. Surgical treatment significantly reduces the risk of Achilles tendon rerupture, but increases the risk of infection, when compared with conservative therapy. Wide confidence intervals around the estimates of risk reduction suggest a large trial is needed to establish risks and benefits.

Achilles Tendon↗
PubMed2002

The biomechanical effect of high-pressure irrigation on diaphyseal fracture healing in vivo.

OBJECTIVES: To evaluate the effect of both high-pressure pulsatile lavage and bulb syringe irrigation on the biomechanical parameters of fracture healing using an in vivo open noncontaminated diaphyseal femoral fracture model in rats. BACKGROUND: The utility of high-pressure pulsatile lavage irrigation on soft tissue debridement has been extrapolated to a similar perceived benefit in the debridement of bone. However, there have been several reports of a possible deleterious effect that high-pressure pulsatile lavage may have on bone architecture, intramedullary bacterial and contaminant seeding, and fracture healing. Although a previous in vivo histologic study suggests damage to bone architecture and impairment of early bone formation, it remains unclear whether these microscopic findings translate to a detectable decline in the biomechanical strength of the healing fracture. To our knowledge, there have been no reports of the in vivo effects high-pressure pulsatile lavage on fracture healing in open diaphyseal fractures. MATERIALS AND METHODS: Using sterile technique, standard open transverse mid-shaft femur fractures were created in thirty-six rats randomized into three groups: a control group underwent retrograde intramedullary pinning only; a bulb syringe irrigation group and a high-pressure pulsatile lavage group underwent identical procedures as the control group, except that the osteotomy site was irrigated with bulb syringe irrigation and high-pressure pulsatile lavage, respectively, before insertion of the intramedullary pin. Six rats from each group were killed at three weeks and six weeks, and the femora was mechanically tested in bending. RESULTS: Mechanical testing of the thirty-six femora revealed that the peak bending force (17.7 +/- 10.2 N) and stiffness (21.2 +/- 5.1 N/mm) of the healing fracture in the high-pressure irrigation group were significantly lower at three weeks when compared with the control (peak force, 28.1 +/- 5.9 N; stiffness, 31.4 +/- 5.8 N/mm) and the bulb syringe (peak force, 27.7 +/- 3.3 N; stiffness, 23.6 +/- 4.5 N/mm) irrigation groups (p < 0.05). The 37 percent lower peak bending force and 32 percent lower stiffness in the high-pressure pulsatile lavage group after three weeks of fracture healing were not present in the femora tested at six weeks. The high-pressure pulsatile lavage group did reveal a trend toward a lower peak bending force and stiffness after six weeks of fracture healing when compared with the control and bulb syringe irrigation groups, but the differences were not statistically significant at the 95 percent level. CONCLUSIONS: The use of high-pressure pulsatile lavage in open noncontaminated diaphyseal femur fractures in rats has a significant negative impact on the mechanical strength of the fracture callous during the early phases (three weeks) of fracture healing. However, it appears that the early deleterious effect of high-pressure pulsatile irrigation is not apparent in the late phases (six weeks) of fracture healing. Further study is required to evaluate the effect of high-pressure pulsatile lavage on fracture healing in the presence of wound contamination, fracture comminution, and soft tissue damage. CLINICAL SIGNIFICANCE: The findings of this study suggest that selective use of high-pressure irrigation in the management of open fractures appears warranted. In situations in which high-pressure lavage may be deleterious to bone healing, alternative strategies that optimize bacterial removal from soft tissues while preserving bone architecture will need to be investigated.

Animals↗
PubMed2002

Three-dimensional assessment of tibial malunion after intramedullary nailing: a preliminary study.

OBJECTIVES: The purpose of this study was twofold: (a) to introduce a new three-dimensional digital assessment technique for the estimation of angular and rotational malunion and (b) to determine if an association exists between tibial malunion and functionally defined post-traumatic degeneration at the knee and ankle joint. DESIGN: Nonrandomized, cohort study, with 5.46 years (range 2 to 10 years) of follow-up. Subjects underwent a novel three-dimensional technique to determine the functional mechanical axis of both the knee and tibiotalar joints. Both the affected and unaffected limbs were tested. Differences between both limbs provided assessment of malunion in three planes with 1.8 +/- 0.1 percent (mean +/- SD) reliability. Patients completed the Western Ontario McMaster University Osteoarthritis Index, the Lower Extremity Functional Scale, and the Assessment System of Lower Extremity Function. Standard postoperative radiographs were also examined for evidence of malunion. SETTING: University-based Level 1 trauma center. PATIENTS: Seventy-one subjects with an isolated tibial fracture repaired with intramedullary nails were identified; thirteen met eligibility criteria for study inclusion. RESULTS: A total of 77 percent of the patients (mean follow-up 5.5 years, range 2 to 10 years) were malaligned in one or more of the three planes examined (malunion conventionally defined as >or=10 rotation, >or=5 varus-valgus, and >or=10 procurvatum-recurvatum). Mean varus-valgus deformity was 11.8 +/- 6.3 degrees, mean procurvatum-recurvatum deformity was 3.2 +/- 2.5 degrees, and medial-lateral rotational deformity was 9.6 +/- 4.7 degrees. There was no significant correlation (p > 0.05) between the overall alignment of the involved leg (intertibial difference) in any of the three directional planes and the subject's response to any of the three functional outcome scales used. Three-dimensional analysis differed significantly from radiographic interpretation when malunion occurred in the coronal plane (p = 0.0003). CONCLUSIONS: This study suggests that failure to meet conventionally accepted standards for tibial alignment might be common. Fortunately, these values were not associated with adverse functional outcomes. A three-dimensional system, which determines the functional mechanical axis of the knee and tibiotalar joints, may be a valuable and reliable method by which to determine malunion after fracture fixation.

Adult↗
PubMed2002

A lack of consensus in the assessment of fracture healing among orthopaedic surgeons.

BACKGROUND: The assessment of fracture healing is both a clinically relevant and frequently used outcome measure following lower extremity trauma. However, it remains uncertain whether there is a consensus in the assessment of fracture healing among orthopaedic surgeons. Variability in the assessment of healing may have important implications in surgeons' decisions to intervene when they perceive fracture healing is slow to progress. OBJECTIVE: To identify surgeons' approaches in the assessment of tibial fracture healing and the definitions of a delayed union, nonunion, and malunion among orthopaedic surgeons. STUDY DESIGN: Cross-sectional survey of 577 orthopaedic surgeons. METHODS: Focus groups, key informants, and sampling to redundancy strategies were used to develop a survey to examine surgeons' opinions in the assessment of tibial shaft fractures. Surgeons were asked how often the following variables were used in the assessment of fracture healing: (a) callus size; (b) cortical continuity; (c) progressive loss of fracture line; (d) pain with weight bearing; and (e) pain to palpation at the fracture site. Further, surgeons were asked to provide a time point beyond which a delayed union becomes a nonunion. Finally, surgeons specified their limits of acceptable fracture alignment (translation, shortening, rotation, varus/valgus, and procurvatum/recurvatum). The survey was pilot tested for clarity and content validity. This survey was mailed to 577 orthopaedic surgeons who were members of the Orthopaedic Trauma Association, American Academy of Orthopaedic Surgeons, and European-AO International-affiliated trauma centers. RESULTS: Responses were obtained from 444 surgeons (response rate 77%). For each variable, the proportion of surgeons who always used the criterion ranged from 39.7% to 45.4%, and those who occasionally or never used the criterion ranged from 20.7% to 26.9%. Surgeons' definitions of delayed union ranged from 1 to 8 months, whereas definitions of nonunion ranged from 2 to 12 months. There was also variability in definitions of fracture malunion. Acceptable degrees of fracture shortening and translation ranged from less than 5 mm to greater than 15 mm. Surgeons' definitions of acceptable angular malunions (rotational, varus/valgus, and procurvatum/recurvatum) ranged from less than 5 degrees to 20 degrees. CONCLUSIONS: There is a lack of consensus in the assessment of fracture healing in tibial shaft fractures among orthopaedic surgeons. Varying definitions of nonunion and malunion may influence the decision to intervene in an effort to promote fracture healing and/or realign the fracture.

Adult↗
PubMed2002

Current practice in the intramedullary nailing of tibial shaft fractures: an international survey.

BACKGROUND: Tibial fractures are the most common of all long bone fractures. Although many tibial fractures may be managed conservatively, a certain subset, including unstable fractures and open fractures, require operative stabilization. Intramedullary nails have become the popular choice of implant in the treatment of tibial shaft fractures. The variability in outcomes with tibial shaft fractures may reflect technical aspects of the surgical procedure and perioperative care regimens among surgeons. Identifying the distribution of surgeons' preferences in nailing technique, and the rationale for their choices, will aid in focusing educational activities for the orthopedic community and planning future clinical trials. Our objectives were to clarify surgeons' opinions regarding technical aspects of surgery and perioperative care after intramedullary nailing of closed and open tibial shaft fractures, and to identify predictors of surgeons' preferences in technique and perioperative care. METHODS: This study was a cross-sectional survey using focus groups, key informants, and sampling to redundancy strategies to develop a survey to examine surgeons' preferences in the treatment of tibial shaft fractures. The survey was pilot tested for clarity and content validity. We mailed this survey in July 2000 to 577 orthopedic surgeons who have an interest in trauma care. These were members of the Orthopaedic Trauma Association, American Academy of Orthopaedic Surgeons, or European AO International affiliated trauma centers. We used several strategies to improve response rates including personalized cover letters, stamped return envelopes, follow-up telephone calls, and repeat mailing of questionnaires. Main outcome measures included technical issues such as reduction, exposure, intramedullary reaming, and interlocking screws; and factors associated with surgeons' preferences such as age, fellowship, academic practice, and geographic location. RESULTS: Four hundred forty-four surgeons (77%) responded. Sixty percent of respondents had an academic practice, 84% supervised residents, and 65.1% had fellowship training in trauma. Approximately half (51.5%) of surgeons used a tourniquet. The odds that a surgeon in Asia or Africa used tourniquets was 10 times that of a North American surgeon (p = 0.004 and p = 0.002, respectively). Patellar tendon retraction and an inferior-based entry portal was the popular choice among surgeons (70.1% and 70.8%, respectively). Surgeons from Australia (odds ratio [OR] = 50, p < 0.001), South America (OR = 9.0, p < 0.001), Europe (OR = 3.7, p = 0.001), and Asia (OR = 3.8, p = 0.006) were significantly more likely to use a patellar splitting approach compared with North American surgeons. In the perioperative care of open tibial shaft fractures, there was consensus in the use of intravenous antibiotics and wound irrigation (96.5% and 95.6%, respectively). However, we found considerable variability in surgeons' preference in wound irrigation pressures (high, 38.7%; low, 45.4%). Surgeons in South America were 10 times more likely to use low-pressure irrigation than North American surgeons (p = 0.0005). In grade IIIB open tibial shaft fractures, 94% of surgeons believed wound closure should be obtained within the first 7 days after the injury. A surgeon's geographic location was a significant predictor of the timing of soft tissue coverage (p = 0.001). CONCLUSION: Consensus in the use of irrigation and intravenous antibiotics in open fractures was achieved among surgeons. However, there remains considerable variability in the surgical technique of intramedullary nailing, the duration of antibiotic use, and the timing of wound closure in open tibial fracture care. Continued education and large multicenter trials are needed to establish best practice in the operative treatment of tibial shaft fracture.

Adult↗
PubMed2002

High-pressure irrigation increases adipocyte-like cells at the expense of osteoblasts in vitro.

High-pressure lavage produces greater visible damage to bone at a macroscopic and microscopic level when compared with low-pressure lavage and can result in delay in the healing of fractures. Osteoblasts and adipocytes are derived from mesenchymal stem cells. Conditions which lead to bone loss often involve a switch from the osteoblast to adipocyte lineage. We have therefore examined the effect of high- and low-pressure irrigation on the differentiation of adipocytes. Calvaria-derived bone cells were exposed to either low-pressure or high-pressure irrigation with normal saline. After 14 days the cells were fixed and the osteoblasts and adipocytes quantified using Oil Red O to stain cytoplasmic lipid droplets (triglycerides) in the cells. Osteoblasts were quantified using a commercially available alkaline-phosphatase staining assay. A standard quantitative reverse transcription-polymerase chain reaction (RT-PCR) was performed. Messenger RNA levels for osteocalcin, a marker of osteoblasts, and PPARy2, a marker of adipocytes, were measured. High-pressure lavage resulted in an increase in adipogenesis of 50% when compared with low-pressure lavage. Our findings suggest that high-pressure lavage may promote differentiation of mesenchymal stem cells towards the adipocyte lineage. This may have clinical significance in the development of delayed and nonunion after treatment of fractures of long bones.

Adipocytes↗
PubMed2002

The quality of reporting of randomized trials in the Journal of Bone and Joint Surgery from 1988 through 2000.

BACKGROUND: The purpose of this study was threefold: (1) to determine the scientific quality of published randomized trials in the American Volume of The Journal of Bone and Joint Surgery from 1988 through 2000, (2) to identify predictors of study quality, and (3) to evaluate inter-rater agreement in the scoring of study quality with use of a simple scale. METHODS: Hand searches of The Journal of Bone and Joint Surgery were conducted in duplicate to identify randomized clinical trials. Of 2468 studies identified, seventy-two (2.9%) met all eligibility criteria. Two investigators each assessed the quality of the study under blinded conditions and abstracted relevant data. RESULTS: The mean score (and standard error) for the quality of the seventy-two randomized trials was 68.1% plus minus 1.6%; 60% (forty-three) scored <75%. Drug trials had a significantly higher mean quality score than did surgical trials (72.8% compared with 63.9%, p < 0.05). Regression analysis revealed that cited affiliation with an epidemiology department and cited funding were associated with higher quality scores. Failure to conceal randomization, to blind outcome assessors, and to describe why patients were excluded resulted in significantly lower quality scores (p < 0.05), more than the 5% decrease expected by removal of each item. A priori calculations of sample size were rarely performed in the reviewed studies, and only 2% of the studies with negative results included a post hoc power analysis. The Detsky quality scale met accepted standards of interobserver reliability (kappa, 0.87; 95% confidence interval, 0.70 to 0.95). CONCLUSIONS: Few studies published in The Journal of Bone and Joint Surgery were randomized trials. More than half of the trials were limited by a lack of concealed randomization, lack of blinding of outcome assessors, or failure to report reasons for excluding patients. Application of standardized guidelines for the reporting of clinical trials in orthopaedics should improve quality.

Humans↗
PubMed2002

An observational study of orthopaedic abstracts and subsequent full-text publications.

BACKGROUND: Research abstracts are frequently referenced in orthopaedic textbooks and influence orthopaedic care. However, little is known about the quality of information provided in the abstracts, the frequency of publication of complete papers after presentation of abstracts, or any discrepancies between abstracts and published papers. The objective of this study was to determine the quality of information provided in orthopaedic abstracts, rates of publication of full-text articles after presentation of abstracts, predictors of publication of full-text articles, and consistency between abstracts and full-text articles. METHODS: We retrieved all abstracts from the 1996 scientific program of the sixty-third Annual Meeting of the American Academy of Orthopaedic Surgeons. For each abstract, we recorded the completeness of reporting and key features of the study design, conduct, analysis, and interpretation. A computerized Medline and PubMed search established whether the abstract had been followed by publication of a full-text article. Finally, we evaluated the consistency of reporting between abstracts and final publications. RESULTS: The program included 465 abstracts, 66% of which were on prognostic studies. All abstracts described the study design, and 70.7% of the designs were observational. Key methodological issues were reported in less than half of the abstracts, and information on data analysis was reported in <15%. One hundred and fifty-nine (34%) of the 465 abstracts were followed by publication of a full-text article. The mean time to publication (and standard deviation) was 17.6 +/- 12 months (range, one to fifty-six months). Inconsistencies between the abstract and the full-text article included the primary outcome measure, which differed 14% of the time, and the results, which differed 19% of the time. CONCLUSIONS: Two-thirds of the orthopaedic abstracts in this sample were not followed by publication of a full-text paper. The overall quality of reporting in abstracts proved inadequate, and inconsistencies between the final published paper and the original abstract occurred frequently. The routine use of abstracts as a guide to orthopaedic practice needs to be reconsidered.

Abstracting and Indexing↗
PubMed2001

An economic evaluation of early versus delayed operative treatment in patients with closed tibial shaft fractures.

There are few reports examining the effect of surgical delay on outcomes following operative treatment of lower extremity fractures. Delays in the surgery for closed tibial shaft fractures have been reported to increase the overall complication rate, postoperative hospital stays and crude costs to the health care system. Our purpose was to estimate the cost-effectiveness and cost-utility associated with the adoption of a programme of early operative treatment of all closed tibial shaft fractures. We performed cost analyses based upon data obtained from an observational study. A cohort of patients with closed tibial shaft fractures was identified at a university-affiliated level I trauma centre. Patients were divided into an early surgical group (within 12 h) and delayed surgical group (longer than 12 h). Study outcomes included time to fracture union (weeks), direct inpatient and outpatient costs associated with each intervention, loss of productivity costs, and utilities (patient health perception) as determined from content experts. Sixteen patients were operated on within 12 h of injury and 19 patients were treated later than 12 h after their fracture. These groups were similar for all baseline variables. The average time to fracture union was 28.2 weeks (SD 9.4) and 44.2 weeks (SD 7.4) for the early surgical group and the delayed surgical group, respectively ( p<0.01). When the costs associated with productivity losses were included in the cost-effectiveness analysis, savings were noted of 7,330 CD dollars per patient and of 458 CD dollars for each week that a fracture healed more quickly with early treatment. However, when the loss of patient productivity was not included, there was a cost per week of 67 CD dollars. A difference of 0.09 quality adjusted life years (QALYs) in favour of the early surgery was found, which yielded a savings of 81,444 CD dollars per QALY gained when the productivity losses were included and a cost per QALY of 11,922 CD dollars when the productivity losses were not included. Both cost-effectiveness and cost-utility analyses were robust. Early plate fixation of closed tibial shaft fractures results in significantly shorter time to fracture union, fewer postoperative complications, significant cost effectiveness and greater QALYs gained when compared with delayed treatment. Inferences from this study are strengthened by the comprehensive abstraction of cost data and detailed cost-effectiveness and cost-utility analyses.

Ambulatory Care↗
PubMed2001

Valgus high tibial osteotomy. Comparison between an Ilizarov and a Coventry wedge technique for the treatment of medial compartment osteoarthritis of the knee.

A matched-pair comparative analysis was done comparing outcomes between a Coventry-type closing wedge valgus high tibial osteotomy (HTO) and an HTO using an Ilizarov apparatus. Thirty patients were treated with a mean follow-up interval of 28.1 months. Functional outcomes were evaluated using the Western Ontario and McMaster University (WOMAC) osteoarthritis index. Clinical and radiographic assessment of the index knee, complications, and over-all satisfaction of the patients were assessed. The procedures were performed between 1994 and 1997. The two groups were equal with respect to baseline demographics - age, sex, body mass index, smoking status. The patients undergoing an Ilizarov HTO had a significantly greater decrease in pain and increase in function at final follow-up assessment. Eleven of the 15 patients in the Ilizarov group were satisfied with the procedure compared to five in the closing wedge HTO group. The treatment of medial compartment osteoarthritis in genu varum of the knee with an Ilizarov apparatus produces outcomes that are comparable to the standard lateral closing wedge osteotomy.

Female↗
PubMed2001

Effect of continuous versus dichotomous outcome variables on study power when sample sizes of orthopaedic randomized trials are small.

It is often not feasible to conduct large trials in orthopaedic surgery. Therefore, surgeons must identify strategies to optimize the statistical power of their smaller studies. The aim of this study was to compare study power in randomized trials with continuous versus dichotomous outcome variables. We performed a systematic review of the literature to identify randomized trials in orthopaedic trauma. Of these, we examined only those trials with small sample sizes (50 patients or less). The outcomes in each eligible study were categorized as continuous or dichotomous. Standard power calculations were performed for each study, and comparisons were made between continuous and dichotomous outcome variables. We identified 196 randomized trials in orthopaedic trauma. Of these, 76 trials had a sample size of 50 patients or fewer (29 trials with continuous outcomes, 47 trials with dichotomous outcomes). Studies that reported continuous outcomes had a significantly higher mean power than those that reported dichotomous variables (power 49% vs 38%, p=0.042). Twice as many trials with continuous outcome variables reached acceptable levels of study power (i.e. >80% power) when compared with trials with dichotomous variables (37% vs 18.6%, p=0.04). When orthopaedic surgeons anticipate small sample sizes for their study, they can optimize their study's statistical power by choosing a continuous outcome variable.

Cluster Analysis↗
PubMedDate not supplied

Bone formation following intramedullary femoral reaming is decreased by indomethacin and antibodies to insulin-like growth factors.

OBJECTIVE: We aimed to: 1). compare rates of in vitro bone formation following reamed and nonreamed intramedullary fixation in a murine model of femoral fracture healing; and 2). examine whether antibodies to insulin-like growth factor (IGF) I, IGF II, or indomethacin (an inhibitor of the inflammatory process) affect bone formation following intramedullary reaming. DESIGN: Experimental study. PARTICIPANTS: Twenty-four C57 black mice were randomized to two groups: reamed ( = 12), and nonreamed intramedullary nail insertion ( = 12). INTERVENTION: In the reamed group, the femoral canals were successively reamed with 30-, 27-, 25-, and 23-gauge stainless steel pins and stabilized with a 27-gauge pin. In mice randomized to the nonreamed group, a 27-gauge pin was inserted. An external three-point bending force created a midshaft transverse femoral fracture. Seven days postsurgery, each mouse was killed, and the right femur was removed. Following pin removal, the callus was minced, the bone marrow was removed, and both were ultracentrifuged at 1200 rpm for 5 minutes. The supernatent was cocultured with 3-day-old murine calvarial cells in culture media. At day 5 of culture, reamed plasma and calvarial cell cocultures were exposed to either 1.0 micro g/mL of anti-IGF I, 1.0 micro g/mL of anti-IGF II, 2 micro M indomethacin, or served as controls (calvarial cells only). The cells were cultured for a total of 21 days. MAIN OUTCOME MEASUREMENTS: The number of bone nodules was quantified by light microscopy. RESULTS: Reamed pin insertion resulted in 4.1-fold and 8.9-fold increases in the mean number of bone nodules compared to pins inserted without reaming and controls, respectively (399 +/- 40.0 vs. 97.0 +/- 21.0, < 0.001). The positive effect of intramedullary reaming on bone nodule formation was reversed with the administration of antibodies to IGF I and IGF II. The addition of anti-IGF I or anti-IGF II to calvarial, or osteoblastlike, cells treated with supernatent from the callus and bone marrow of mice with prior intramedullary reaming resulted in significant declines in the mean number of bone nodules ( < 0.001). Specifically, treatment of osteoblastlike cells with anti-IGF I or anti-IGF II resulted in 7.0-fold and 5.4-fold declines in mean bone nodule formation compared to cells without such treatment. CONCLUSIONS: Intramedullary reaming prior to pin insertion resulted in a significantly greater number of bone nodules than pin insertion only. Antibodies to IGF I, IGF II, and indomethacin reversed the stimulatory effect of reaming on bone nodule formation, suggesting their role in modulating the course of fracture healing following intramedullary reaming.

Animals↗