MRI of the knee after locked unreamed intramedullary nailing of tibia

We analysed the reason for knee pain after intramedullary (IM) nailing with standard MRI sequences at a mean of 27 months (range 2–45) after nail removal in eleven patients with a mean age of 30 years (range 15–52). Knee pain was assessed in four grades. All our patients had signal changes of fluid in the nail channel, areas of low signal intensity in Hoffa’s fat pad and subcutaneous low signal nodes in front of a thickened patellar ligament. Ten patients had low signal adhesions from the nail insertion towards the patellar ligament. Six patients had severe knee pain and even marked adhesions. Two patients had no knee pain; one of these two had minimal adhesions and the other one no adhesions. Five of the patients had a meniscal tear and/or local cartilage reduction. The degree of adhesions from the nail insertion in the tibia towards the patellar ligament was proportional to the degree of knee pain. No sign of acute inflammation was found. Abstract presented, in part, at the European Society of Musculoskeletal Radiology Annual Meeting, 13–14 June 2003, Aarhus, Denmark.     

Fracture healing after reamed and unreamed intramedullary nailing in sheep tibia

Intramedullary nailing is a well-established method for stabilisation of long-bone shaft fractures. It is still a controversy as to whether the procedure should be done by an unreamed or reamed technique.In the present animal study, 24 sheep were treated with intramedullary nailing. Midshaft fractures (Arbeitsgemeinschaft für Osteosynthese (AO) type 42-A2/3) were created. Eight sheep were treated with an unreamed nailing technique (UN), a further eight sheep underwent tibia nailing by the reamed technique using the conventional AO reaming system (RC) and in a further eight sheep, reamed nailing was performed using an experimental reaming system (RE). Intra-operatively, the intramedullary pressure was measured and, during a healing time of 10 weeks, the growth of callus formation was labelled with fluorescence markers after 4 and 6 weeks. After 10 weeks, the animals were euthanised and the quality of fracture healing was determined by recording stiffness in torsion, antero-posterior and mediolateral bending and the load at yield. In addition, the callus formation at the fracture zone was evaluated by fluorescence microscopy and macroradiographs.The results showed a decrease of intramedullary pressure when reamed nailing was performed with the RE (72.5 mmHg) system compared with the conventional AO reaming system (227 mmHg). Mechanical testing did not reveal any significant differences either for torsional or bending stiffness or for load at yield for any of the three procedures. Histological evaluation showed a similar callus formation for the UN group and the RE group. Callus formation in the UN (65 mm²) and RE (63 mm²) groups showed a higher increase during the first 6 weeks than those treated with the conventional AO reaming system (27 mm²). This means that, especially during the first weeks of fracture healing, damage to the bone by the reaming process can be reduced by reaming with a reaming device with lowered cutting flutes and smaller drive-shaft diameter.Intramedullary pressure can be significantly reduced by using reaming systems with reduced drive-shaft diameters and deepened cutting flutes. In the early phase of fracture healing, callus formation can be influenced positively when using the RE system.     

Open grade III fractures of tibia: outcome after early unreamed intramedullary nailing

Open grade III fractures of tibia are challenging therapeutic problem even to experienced surgeons. Method for skeletal stabilization of these fractures remained a topic of controversy. One hundred and two patients with 103 open grade III fractures of tibia were included in the study. They were treated with early unreamed intramedullary nailing with the adequate management of soft tissue. Patients were reviewed retrospectively. Mean time of union was 35 weeks. Six tibial fractures had nonunion. Infection rate was 14% in open grade III tibial fractures. No case of angular or rotational deformity was noted. In conclusion, early unreamed intramedullary nailing for open grade III fractures of tibia after giving due respect to the soft tissue injury gives good outcome with proper alignment, good range of motion, short rehabilitation period and low infection rate.     

Pulmonary fat embolism after reamed and unreamed nailing of femoral fractures

Background

To determine whether reamed or unreamed intramedullary nailing of femoral fractures results in higher incidence of pulmonary fat embolism, three different methods of intramedullary nailing were compared in sheep. To analyze the presence of bone marrow fat embolism in pulmonary arteries, histological evaluation was undertaken using a quantitative computer-assisted measurement system.

Methods

In this experimental model of 27 female Swiss alpine sheep, an osteotomy of the proximal femur was conducted in each animal. Then, the animals were divided into three groups according to the method of treatment: two different reamed intramedullary nailing techniques and an unreamed nailing technique were used.In the first group “ER” (experimental reamer; n = 9), the nail was inserted after reaming with an experimental reamer; in the second group “CR” (conventional reamer; n = 7), the intramedullary nail was inserted after reaming with the conventional AO-reamer. In the third group “UN” (unreamed; n = 8) unreamed nailing was performed. During the operation procedure intramedullary pressure was measured in the distal fragment.After sacrificing the animals, quantitative histological analyses of bone marrow fat embolism in pulmonary arteries were done using osmium tetroxide fixation and staining of the fat.

Results

The measurement of intramedullary pressure showed significantly lower values for reamed nailing than for the unreamed technique. The quantitative histological evaluation of lung vessels concerning bone marrow fat embolism revealed a statistically significant difference between reamed and unreamed insertion of the nail: 7.77% ± 6.93 (ER) and 6.66% ± 5.61 (CR) vs. 16.25% ± 10.05 (UN) (p < 0.05) of the assessed lung vessels were filled with fat emboli. However, no difference was found between the traditional and experimental reamer.

Conclusions

Intramedullary nailing after reaming is a safe procedure with low systemic embolisation when compared to the unreamed insertion of the nail.     

Primary unreamed intramedullary nailing for open fractures of the tibia

Forty-six open tibial fractures (42 patients) were treated by primary unreamed intramedullary nailing, with debridement of open wounds and treatment of soft tissue. According to Gustilo-Anderson classification there were 18 grade I cases, 18 grade II cases and 10 grade III cases. The incidence of infection was low with two cases of superficial infection and one of deep infection. The mean time for union was 21.9 weeks and the rate of nonunion was 10.8%. There was no significant difference in the mean time to union, infection rate and rate of nonunion with different site and grade of fracture, but there was a longer union time and a higher rate of nonunion in complex and comminuted fractures. Unreamed intramedullary nailing, with appropriate soft tissue treatment, gives good results in the treatment of open tibial fractures including grade III.     

Compartment syndrome after intramedullary nailing of the tibia

Three patients had compartment syndrome of the leg after tibial intramedullary nailing with reaming. They were all treated successfully with emergency fasciotomy. A prospective study was done of seven additional patients who had continual monitoring of the pressure in the deep posterior compartment during tibial intramedullary nailing with reaming. In five of them, the procedure was performed three weeks or less after injury and in the remaining two, the nailing was performed later for the treatment of non-union. Two pressure peaks in the deep posterior compartment were noted: one after strong longitudinal traction was applied and the fracture was reduced and the other during intramedullary reaming. Intraoperative pressure of thirty millimeters of mercury or more were recorded in three of the seven patients. In the treatment of tibial fractures, operative procedures that involve forceful traction for a long time may predispose the patient to compartment syndrome in the leg. Close clinical observation of such patients is needed. When there is a high risk of compartment syndrome, monitoring of the pressure in the compartment may be prudent.     

Transesophageal echocardiography in quantification of emboli during femoral nailing: reamed versus unreamed techniques

We quantified the embolic load to the lungs created with two different techniques of femoral nailing. Eleven patients with 12 traumatic femur fractures were randomized to reamed (7 fractures) and unreamed (5 fractures) groups. Intramedullary nailing was with the AO/ASIF* universal reamed or unreamed nail. Transesophageal echocardiography (TEE) was used to evaluate the quantity and quality of emboli generated by nailing. Data were analyzed using software that digitized the TEE images and quantified the area of embolic particles in each frame. The duration of each level of embolic phenomena (zero, moderate, severe) was used to determine total embolic load with various steps (fracture manipulation, proximal portal opening, reaming, and nail passage). Manual grading of emboli correlated highly with software quantification. Our data confirm the presence and similarity of emboli generation with both methods of intramedullary nailing. Unreamed nails do not protect the patient from pulmonary embolization of marrow contents.     

Compartment pressures after intramedullary nailing of the tibia

Intracompartmental pressures of 66 patients with 67 tibial fractures treated by intramedullary nailing were monitored. There was no difference in the pressures recorded between the different Tscherne fracture types, between open and closed fractures, between low energy and high energy injuries or between fractures dealt with early and those not treated until more than 24 hours after injury. The overall incidence of acute compartment syndrome was 1.5%. No patient developed any sequelae of compartment syndrome. We conclude that intramedullary nailing does not increase the incidence of acute compartment syndrome in tibial fractures and that delay does not reduce the risk of raised compartment pressures.     

Fat emboli syndrome in a nondisplaced tibia fracture

Fat emboli syndrome is a well-recognized complication of displaced long bone fractures, often times requiring internal fixation. Treatment is generally supportive and is most successful with early diagnosis. This article describes a case of fat emboli syndrome resulting from a nondisplaced tibia fracture treated with long leg casting. This case demonstrates that fat emboli should be considered as a potential complication of any long bone fracture and should be part of the differential diagnosis for any patient unconscious or in respiratory distress that has sustained a recent long bone fracture.     

Intramedullary pressure and bone marrow fat extravasation in reamed and unreamed femoral nailing.

This study was designed to investigate whether intramedullary pressure and embolization of bone marrow fat are different in unreamed compared with conventional reamed femoral nailing in vivo. In a baboon model, the femoral shaft was stabilized with interlocking nailing after a midshaft osteotomy. Intramedullary pressure was measured in the distal femoral shaft fragment at the supracondylar region. Extravasation of bone marrow fat was determined by the modified Gurd test (range: 0-5) with blood samples from the vena cava inferior. Data were monitored in eight unreamed and eight reamed intramedullary femoral nailing procedures. Intramedullary pressure increased in the unreamed group to 76 +/- 25 mm Hg (10.1 +/- 3.3 kPa) during insertion of 7-mm nails and in the reamed group to 879 +/- 44 mm Hg (117.2 +/- 5.9 kPa) during reaming of the medullary cavity. Insertion of 9-mm nails after the medullary cavity had been reamed to 10 mm produced an intramedullary pressure of 254 +/- 94 mm Hg (33.9 +/- 12.5 kPa) (p < 0.05). Fat extravasation in the unreamed group was recorded with a score of 2.9 +/- 0.4 for the Gurd test during nailing with 7-mm nails, whereas in the reamed group significantly more fat extravasation was noticed during the reaming procedures, with a score of 4.6 +/- 0.1. Liberation of fat during insertion of 9-mm nails after reaming was recorded with a score of 3.5 +/- 0.4. In both groups, a positive correlation of fat extravasation with the rise in intramedullary pressure was found (reamed group: r(s) = 0.868; unreamed group: r(s) = 0.698), resulting in significantly less liberation of bone marrow fat in the unreamed stabilized group than in the reamed control group (p < 0.05). The data indicate that fat embolization during nailing procedures after femoral osteotomy increases with increasing intramedullary pressure and occurs in a lesser degree in unreamed than in reamed intramedullary femoral shaft stabilization.     

Open tibial fractures: faster union after unreamed nailing than external fixation

Unreamed intramedullary nailing is an alternative to external fixation in the treatment of open tibial fractures. We compared a prospective series of thirty-one patients managed with a solid nail with static interlocking without intramedullary reaming, with a retrospective series of thirty-one patients managed by external fixation. The protocol for soft tissue treatment was the same throughout the study period. Most fractures were caused by high energy trauma and included Grade I to III B injuries. The fracture wound infection rate was equal in both groups; there were two deep and three superficial infections in the nail group and three deep and two superficial infections in the external fixation group. In addition, eleven patients in the external fixation group had severe pin track infections. The mean time to union was five months in the nail group and eight months in the external fixation group. The incidence of delayed union was twice as high in the external fixation group as in the nail group. The number of surgical procedures performed to promote union was three times higher in the external fixation group. The malunion rate did not differ between the groups. Although the treatment groups are not fully comparable, the results indicate that intramedullary nailing is superior to external fixation in the treatment of most open tibial fractures.     

"Biorigid" interlocking after unreamed intramedullary nailing of tibial shaft fractures

Between April 1996 and December 1999, 76 tibial shaft fractures were treated at the Department of Trauma Surgery of the Justus-Liebig-University in Giessen, Germany and the Department of Orthopedic Surgery of the University of Louisville, USA with a newly developed, unreamed, solid, small diameter tibial nail interlocked "biorigidly" with screws in grooves of the nail. 69 Patients were reviewed with a minimal follow-up period of 16 months. In 65 patients, the fractures united without exchange nailing, although four of these fractures showed a delay of healing. In further four cases, non-union occurred, one of which was associated with the only break of a nail located at a distal interlocking groove of the nail. In one patient, a late medullary infection so far has not recurred following treatment. In 358 implanted interlocking screws, no implant failure was observed. First clinical experience suggests that, especially due to the low rate of material fatigue, the biorigid nail is an alternative to other implants for unreamed intramedullary nailing of the tibia.     

Delayed intramedullary nailing after failed external fixation of the tibia

Thirteen patients (11 males, two females) with 16 tibia fractures (three segmental) were initially treated with external fixation and secondarily had delayed intramedullary nailing after fixator removal. There were six closed injuries and two Grade I, five Grade II, one Grade IIIA, and two Grade IIIB open soft-tissue injuries. The average patient age was 40 years (range, 19-84 years). The external fixator was removed at an average of 12 weeks (range, three to 25 weeks) for malreductions in six case, atrophic segmental fractures in two, and atrophic/unstable fracture patterns in five. Intramedullary nailing was performed at an average of 13 days (range, five to 30 days) after fixator removal. There were 12 reamed nails and one self-broaching nail. Preoperative antibiotics averaged eight days, and postoperative averaged 11 days. All patients healed with bridging callus; full weight bearing occurred at an average of 2.7 months. Follow-up evaluation averaged 22.5 months. Weight bearing began within the first three weeks in 12 of 13 patients. Results were rated as excellent in eight and good in five. There were no complications related to infection or non-union. Delayed intramedullary nailing, after excluding potential high-risk patients, is an option for the treatment of tibia fractures that have failed treatment with external fixation. However, it is not recommended as a routine procedure.     

扩髓与非扩髓型股骨髓内针术后免疫因子释放水平的研究

目的通过检测部分免疫介质的释放水平,探讨在应用髓内针治疗股骨干骨折术后早期对机体免疫功能的影响.方法选择股骨干闭合骨折患者59例,男55例,女4例,平均年龄32.1岁,按伤情分为轻伤组(n=43)和中度伤组(n=16),采取闭合复位带锁髓内针固定治疗.轻伤组扩髓23例、非扩髓23例,中度伤组扩髓7例、非扩髓6例,分别于术前24 h和术后1、24、48 h通过ELISA法检测患者血中TNF、IL-6、IL-8、IL-10的水平,通过蛋白分析测定CRP的水平;同时选取22例健康志愿者作为正常对照组.结果轻、中度创伤患者术后各炎症指标均较术前有所上升;IL-6、IL-8、IL-10在术后1 h呈上升趋势,术后24 h达到高峰,术后48 h 三种因子水平均开始下降,但尚未恢复正常;TNF、CRP术后1 h仍较术前有所下降,但在术后24 h均出现明显上升,到术后48 h再次回落;轻伤与中度伤组不同时段的免疫指标均与对照组有明显差异(P《0.05).不同伤情患者扩髓后各免疫指标均高于非扩髓者,但除中度伤组中IL-10在术后24 h有差异显著性意义(P=0.047)外,其它指标差异均无显著性意义(P》0.05). 2例患者术后出现SIRS,观察发现与非SIRS患者相比各项免疫指标并无显著差别.结论对于轻、中度创伤患者,髓内针会造成机体免疫介质再次大量释放,但经机体免疫调节后不会产生严重的影响;不同方式髓内针固定对术后早期机体的免疫系统的影响没有显著的差异,但以IL-10为代表的免疫抑制因子很可能随着伤情的加重在应用髓内针,尤其是扩髓型髓内针时出现短期内大量释放,从而加重机体的免疫抑制.