Successful use of reaming and intramedullary nailing of the tibia

The records and radiographs of 87 patients with 88 fractures of the tibial diaphysis who underwent intramedullary reaming and nailing were retrospectively reviewed. The mean patient age was 37 years. Seventy fractures were closed, and 18 were open. The indications for nailing were failures of closed treatment (n = 48), nonunions (n = 24), multiple injuries (n = 14), and fixation of osteotomy (n = 2). Seventy-six patients with 77 nails who were followed for an average of 26.2 months were studied. For acute fractures, the average time to complete clinical and radiographic union was 5.3 months. For established nonunions, the average healing time was 9 months. The only fractures that failed to unit were nonunions developing from previously open Type III injuries. Angular deformities greater than 5 degrees did not occur. Significant tibial shortening occurred in only one fracture. Decreased motion in the ankle or knee was present in six patients. Major complications as a result of tibial nailing occurred in three patients: two deep infections and one patellar tendon rupture. Minor complications included 10 patients with pain at the nail insertion site necessitating removal in four patients, three patients with transient sensory peroneal nerve dysesthesias, and one patient with a superficial wound infection that cleared with local care. Nine patients required reoperation. Intramedullary reaming and nailing of the tibia can be used advantageously in the treatment of difficult fractures of the tibial shaft and their sequelae. Attention to the technical details of nail insertion will minimize the most frequent complications.     

Treatment of open tibial-shaft fractures. External fixation and secondary intramedullary nailing

Between 1979 and 1986, sixteen of 369 open fractures of the tibial shaft were treated by external fixation followed by intramedullary nailing. These fractures comprised one Type-I, two Type-II, and thirteen Type-III injuries. This method of treatment was the original treatment plan in nine patients (56 per cent), for delayed union while the external fixator was still in place in four patients (25 per cent), for loss of reduction in a plaster cast in two patients (13 per cent), and for osteomyelitis and a segmental defect in one patient (6 per cent). The average duration of external fixation was 8.5 weeks; the average time between removal of the external fixator and intramedullary nailing, three weeks; and the average time between injury and nailing, twelve weeks. All sixteen patients were followed until either the fracture had united (eleven patients) or there was an established non-union (five patients). At that time, seventeen additional procedures were performed, including bone-grafting, fibulectomy, and re-nailing. Only five of the sixteen fractures healed without additional surgical procedures or major complications. The five fractures that progressed to a non-union were all Type III, and all were complicated by a deep infection. Over-all, the complications included seven deep infections (an intramedullary infection in four patients, osteomyelitis in two, and a chronic draining sinus associated with a ring sequestrum in one); five minor infections during external fixation, which developed into five of the seven deep infections that occurred after the secondary intramedullary nailing; and eight non-unions, three of which progressed to union after multiple procedures. The over-all incidence of non-union was 50 per cent and that of deep infection, 44 per cent. On the basis of the high incidence of complications in both the present series and the few reports in the literature, we concluded that alternative treatment options should be carefully considered before electing this sequential method of fixation.     

Treatment of open fractures of the tibial shaft with the use of interlocking nailing without reaming.

Fifty open fractures of the tibial shaft that were treated with débridement and interlocking nailing without reaming were followed for an average of twelve months. Most of the fractures were the result of high-energy trauma, and 68 per cent of the fracture wounds were grade III. Forty-eight (96 per cent) of the fifty fractures united at an average of seven months; there were no malunions. There were four infections (8 per cent), all at the sites of grade-III fractures. Locking screws broke in five tibiae (10 per cent), but the breakage did not result in a loss of reduction. Three nails broke, two at the sites of ununited fractures and one at the site of a healed fracture. These results are comparable with, or better than, those obtained with other forms of fixation, including immobilization with a cast, unlocked intramedullary nailing, and external fixation.     

交锁髓内钉治疗胫骨下段骨不连

目的:探讨交锁髓内钉治疗胫骨下段骨不连的有效性。方法:2000年4月-2004年2月,应用交锁髓内钉治疗胫骨下段骨不连45例,男28例,女17例;年龄20~58岁,平均38岁。其中肥大型18例,萎缩型14例,营养不良型13例。骨折冠状面成角0°~22°,平均8°;矢状位成角为0°~16°,平均5°。从受伤到交锁髓内钉固定时间为5~12个月,平均7个月。原始创伤为开放性骨折12例,闭合性骨折33例。无大于1.5 cm的节段性骨质缺损。4例胫骨下段肥大型骨不连闭合置入髓内钉,折端未植骨;4例胫骨下端骨不连(肥大型1例,营养不良型3例)应用改良髓内钉治疗。所有病例均采用静力型固定。结果:经7~14个月(平均10个月)随访,44例经3~5个月获得愈合,平均愈合时间3.8个月。1例术后8个月骨折未愈合,经切开植骨、辅助石膏外固定3个月后愈合。术后无活动性感染及慢性骨髓炎发生。结论:交锁髓内钉固定治疗胫骨下段骨不连具有良好的矫正畸形能力和最少量软组织剥离的优点。     

带锁髓内钉在下肢骨干多段骨折的应用

目的：探讨带锁髓内钉在下肢骨干多节段骨折应用的临床疗效及有关问题。方法：回顾性分析31例股骨、胫骨干多节段骨折应用带锁髓内钉的临床资料，有关适应证、切开复位、扩髓及动力和静力固定问题进行讨论。结果：31例中除2例失访，29例随访8～31个月，平均随访12．5个月，关节功能恢复优良率93．1％，骨折愈合率98．3％。结论：只有掌握好操作技术，带锁髓内钉是目前治疗下肢骨干多节段骨折的一种良好内固定方法，值得推广应用。     

Indirect reduction and tension-band plating of tibial non-union with deformity.

Thirty-three patients who had a maligned non-union of the tibial diaphysis were treated by limited open exposure, indirect reduction with a femoral distractor, tension-band plating, lag-screw fixation, and autogenous bone-grafting. The time from the injury to treatment of the non-union averaged twenty-nine months. Twenty-two of the fractures were originally open and sixteen fractures had had a previous infection before treatment of the non-union. The non-unions were classified as hypertrophic in eight patients, oligotrophic in eighteen, and atrophic in seven. All had severe deformity, or the nature or level of the non-union, or both, precluded intramedullary nailing as a treatment option. All thirty-three non-unions healed at an average of four months; the average length of follow-up was nineteen months. The deformity was corrected, within acceptable limits, in thirty-two of the patients. Full motion of the knee was achieved in twenty-nine patients and of the ankle, in eighteen. Complications included four instances of superficial skin breakdowns, one deep infection, and one fracture of the plate. For non-unions of the tibial diaphysis with deformity that are not amenable to intramedullary nailing, the techniques of limited exposure, indirect reduction, tension-band plating, and bone-grafting can yield excellent anatomical and functional results.     

Nonunions of the distal tibia treated by reamed intramedullary nailing

OBJECTIVE: The purpose of this study is to determine the efficacy of reamed intramedullary nailing in the treatment of nonunions of the distal one-fourth of the tibia. Nonunions of the distal tibia are particularly difficult to treat given the short distal segment, the proximity to the ankle joint, and the fragile soft-tissue envelope. Intramedullary nailing is an attractive solution to this problem because it avoids extensive dissection, and the implant remains intraosseous, posing minimal problem for the soft tissues. DESIGN: Retrospective review of patient charts and radiographs. SETTING: Tertiary care orthopaedic hospital. PATIENTS/PARTICIPANTS: Thirty-two patients with nonunions of the distal one-fourth of the tibia. Prior treatments included casting, internal fixation with plates and screws, intramedullary nailing, and external fixation. Seven patients had a history of infection, but no patient had signs of active infection at the time of surgery. INTERVENTION: Study patients were treated by reamed, locked intra-medullary nailing. MAIN OUTCOME MEASUREMENTS: Main outcome measurements included time to union, correction of deformity, and complications including infection and reoperation. RESULTS: Average length of follow-up was 25 months (range 4-81 months). Twenty-nine out of 32 patients achieved union at an average of 3.5 months after reamed, locked intramedullary nailing. Of the remaining three, 2 patients united after dynamization (one at 4 months after dynamization and the other at 7 months), and the third patient united 4 months after exchange nailing. Deformity was corrected to a maximum of 4 degrees in all planes. Four patients had positive intraoperative cultures, and only 2 required removal of the nail after achieving union to control infection. There were no signs of chronic osteomyelitis in these 2 patients at the date of the last follow-up visit; 5.5 years and 2 years following nail removal. CONCLUSIONS: Reamed, locked intramedullary nailing is a reliable and safe procedure in the treatment of nonunions in the distal one-fourth of the tibia, even in the setting of prior infection or external fixation. It allows for excellent correction of deformity, which is an essential component of the procedure.     

Treatment of aseptic diaphyseal nonunion of the lower extremities with exchange intramedullary nailing and blocking screws without open bone graft

Objective: To report the preliminary results of the treatment of aseptic diaphyseal nonunion of the lower extremities with exchange nailing plus blocking screws. Methods: Between June 2005 and September 2008, twelve patients with diaphyseal nonunion in the lower extremities (femur in five patients and tibia in seven; hypertrophic nonunion in eight patients and atrophic nonunion in four) were treated by reaming, exchanging the original intramedullary nail with a larger one, and using blocking screws, and the therapeutic effect assessed. Results: All patients were followed up for 1–2 years (average, 1.5 years) to assess union. Bony union was achieved in all patients within 4.7–13.5 months (average, 7.8 months). All patients were pain free without any complications by the last follow‐up. Conclusion: The therapeutic method of exchanging the nail combined with blocking screws is effective for aseptic nonunion of the lower extremity after intramedullary nailing.     

Locked intramedullary nailing in treatment of femur and tibia delayed union and pseudoarthrosis]

Five patients treated operatively on account of tibia and femur shaft delayed union and pseudoarthrosis were re-operated by locked intramedullary nailing. The method permits stable bone fixation. Intramedullary canal reaming stimulates bone union, as it refreshes fracture site and is a source of bone graft. Intramedullary nail covers anatomical axis of bone and, in the case of femur, is close to its mechanical axis. It diminishes the risk of implant breakage. The method permits active and efficient rehabilitation. Some fractures stabilised with external fixator or operated by Zespol or Polfix method can be re-operated by close technic. It shortens time of operation and diminishes its aggressiveness. In our opinion locked intramedullary nailing is an efficient method in treatment of tibia and femur shaft delayed union and pseudoarthrosis.     

Effect of smoking on tibial shaft fracture healing

Of 146 consecutive closed and Grade I open tibia shaft fractures treated with cast immobilization, external fixation, or intramedullary rod fixation during a 4-year period, 44 of 76 (58%) tibias of patients who smoked and 59 of 70 (84%) tibias of patients who did not smoke had followup to union or followup beyond 1 year. The demographics, fracture patterns, and treatments of the two groups were similar. Two of the 44 patients who smoked had nonunions at the 1-year followup, whereas none of the patients who did not smoke had nonunions. Of the 103 tibias with complete followup to union, the median time to clinical healing for patients who smoked (269 days) was significantly greater than that of patients who did not smoke (136 days). Likewise, there was a 69% delay in radiographic union in the group that smoked as interpreted by a radiologist blinded to the two groups. Statistical differences in clinical and radiographic healing rates between those who smoked and those who did not smoke were observed for patients receiving intramedullary fixation or external fixation. Statistical differences were not seen in the clinical and radiographic healing of tibias treated with cast immobilization, although tibias of patients who smoked took 62% longer to heal. The current data suggest that tibias of patients who smoke who require treatment with intramedullary nailing or external fixation require more time to heal than do those of patients who do not smoke.     

可膨胀髓内钉治疗四肢长骨骨折

[目的]探讨可膨胀髓内钉Fixion^TM系统治疗长管状骨骨折的临床应用效果。[方法]自2004年9月．2006年1月，共30例患者采用Fixion^TM可膨胀髓内钉系统（Disco-O-tech Herzliya，lsreal）进行治疗；所有患者均为外伤引起的四肢长管状骨骨折，其中男17例，女12例，年龄22—82岁；开放性骨折1例，骨不连患者1例；股骨转子间骨折7例，股骨干骨折9例，肱骨骨折7例，胫骨骨折7例。可膨胀自锁髓内钉（IM）18例，可膨胀交锁髓内钉（IL）5例，股骨近端髓内钉（PF）7例。一般术后10d允许患者部分负重，若负重时患者骨折处出现明显疼痛应推迟。[结果]本组30例伤口全部I期愈合，手术时间30～140min，平均65min，术中出血50～1200ml，平均300ml。30例患者全部获得随防，随访时间12～72周，平均40周。术后根据临床和影像学平均愈合时间为：股骨转子间骨折11周，股骨干骨折12．2周，胫骨干骨折13周，肱骨骨折11周。其中1例为肱骨干骨折术后骨不连，再次手术后3个月，骨折处骨痂形成。[结论]可膨胀髓内钉应力分布均匀，避免了应力遮挡效应；一般无需扩髓和锁钉．减少了创伤和手术时间，医生和患者接受的X线剂量少和感染率低；轴相弹性动力化固定，加快了骨折愈合时间，避免了交锁髓内钉2次动力化手术给病人带来肉体和精神上的痛苦等。临床初步应用疗效满意，为长管状骨骨折的治疗提供一种新型的理念和固定技术，在掌握好适应证、正确操作的前提下，采用Fixion^TM可膨胀髓内钉系统治疗长管状骨骨折有可能获得较传统交锁髓内钉更好的效果。     

Tibia nonunions treated by interlocked nailing: increased risk of infection after previous external fixation

Eighteen patients, mean age 36 years (range of 22-76 years), with tibia-shaft nonunions were treated with interlocked nailing. There were 12 nonunions originally treated with either cast, lag screws, plate, or Ender nails (nine closed, two open grade I and one grade II injury). The remaining six nonunions, all open fractures (five grade II and one grade III injury) initially received external fixation. After removal of the fixator, 72 days postinjury (range of 58-111 days), there was a delay of 218 days (range of 112-449 days) before the nailing procedure in those patients primarily treated with external fixation. All 12 nonunions not primarily treated with external fixation healed without complications after nailing within 17 weeks (range of 12-24 weeks). All six nonunions primarily treated with external fixation had temporary pin-tract infections, which healed after pin extraction. Two of the nonunions healed without any complication, whereas four developed intramedullary infection with the same bacteria as from the pin-tract site. Although the number of patients is small in this report, there is an apparently high incidence of intramedullary infection in the group originally treated with external fixation. The sequential procedure of external fixation followed by intramedullary nailing is, therefore, not recommended in the treatment of open tibia fractures.     

The diaphyseal aseptic tibial nonunions after failed previous treatment options managed with the reamed intramedullary locking nail

BackgroundThe nonunion of open and closed tibial shaft fractures continues to be a common complication of fractures. Tibial nonunions constitute the majority of long bone nonunions seen by orthopaedic surgeons. In this article, we present our approach to the surgical treatment of noninfected tibial shaft nonunions.MethodsBetween 2008 and 2014, 33 patients with aseptic diaphyseal tibial nonunion was treated by reamed intramedullary nailing and were retrospectively reviewed. The initial fracture management consisted of external fixation (27 patients), plate fixation (2 patients) and cast treatment (4 patients). All patients, preoperatively, were evaluated for the signs of the infection, by the same protocol. There were 13 hypertrophic, 16 oligotrophic (atrophic) and 4 defect nonunions registered in our material. The primary goal was to perform a closed intramedullary nailing on antegrade manner. An open procedure was only unavoidable when implants had to be removed or an osteotomy had to be performed to improve the alignment. Functional rehabilitation was encouraged with the assistance of a physiotherapist early postoperative. Patients were examined regularly during followed-up for a minimum of 12 months period for clinical and radiological signs of union, infection, malunion, malalignment, limb shortening, and implant failure.ResultsThe time that elapsed from injury to intramedullary nailing ranged from 9 months to 48 months (mean 17 months).Open intramedullary nailing was unavoidable in 25 cases (75,75%), while closed nailing was performed in 8 patients (24,25%). Osteotomy or resection of the fibula was performed in 78,8% of the cases. All patients were followed up in average period of 2 years postoperative (range 1–4 years), and 31(93,9%) patients achieved a solid union within the first 8 months. Mean union time was 5±0.8 months. Complications included 2 (6,06%) patients, one with deep infection and another case with absence of bone healing. Anatomical alignment has been achieved in the majority of patients, 28 patients (84,8%). The additionally autogenous bone chips were added in 4 patients (12,1%) where cortical defect was greater than 50% of the bone circumference.ConclusionIn conclusion, a reamed intramedullary nail provides optimal conditions for stable fixation, good rotational control, adequate alignment, early weight-bearing and a high union rate of tibial non-unions. Reaming of the medullary canal with preservation of periosteal sleeve create the "breeding ground" for sound healing of tibial shaft nonunions. Additionally cancellous bone grafting is recommended only in the case of defect nonunion.     

Intramedullary nailing of open fractures of the femoral shaft

The cases of eighty-six patients in whom eighty-nine open fractures of the femoral shaft had been treated by intramedullary nailing with reaming were retrospectively reviewed. Twenty-seven fractures were classified as grade-I open fractures; sixteen, as grade-II open fractures; and forty-six, as grade-III open fractures. Immediate intramedullary nailing was done for fifty-six fractures, and delayed stabilization (five to seven days after delayed closure of the wound) was done for thirty-three fractures. A prerequisite for immediate intramedullary nailing was that irrigation and debridement of the open wound be done within eight hours after injury. All fractures healed in an average of 5.2 months. No infections occurred in the sixty-two grade-I, grade-II, or grade-IIIA open fractures, regardless of whether immediate or delayed intramedullary nailing was performed. Of the twenty-seven grade-IIIB fractures, infection developed in three: in one after immediate intramedullary nailing and in two after delayed intramedullary nailing. We concluded that, if a thorough and timely debridement can be accomplished, immediate intramedullary nailing of grade-I and grade-II open fractures of the femoral shaft does not increase the risk of postoperative infection. Selected patients who have a grade-III open fracture may be candidates for immediate intramedullary stabilization, depending on the degree of the patient's associated injuries and the extent of disruption and contamination of the soft tissues of the thigh.     

Anterograde femoral nailing with a reamed interlocking titanium alloy nail

Intramedullary nailing has become the gold standard for treatment of femoral diaphyseal fractures. Between March 1995 and December 1998 we performed 40 intramedullary nailings using the ACE femoral nail (De Puy). The patients were followed for an average of 27.9 months (range: 6-54 months). The mean age was 33.2 years (range: 17-87 years); the sex distribution was 33 males and 7 females. All fractures were unilateral (right 18, left 22). Most of the fractures were caused by traffic accidents (35), the others originated from sports, work and gunshot (1). Thirty-five fractures were closed and 5 were open: 1 was grade I, 2 were grade II and 2 grade IIIa according to Gustilo's classification. According to the AO classification 18 fractures were type A, 13 type B and 9 type C. The majority of patients had associated injuries: neurotrauma 2, chest trauma 2, and other fractures e.g. of the clavicula, lumbar spine, patella, tibia. Immediate surgery was performed in 34 cases, delayed surgery in 6 cases. All fractures were treated on a fracture table, with closed reduction, reaming of the intramedullary canal, proximal and distal locking and intraoperative control of rotation and length. The mean time to healing was 17.85 weeks (range: 18-50 weeks). The following complications were observed: 3 delayed unions, which united after dynamisation, one malunion, which required corrective osteotomy, and one nonunion, which healed after exchange nailing. We encountered no rotational deformity and no clinically relevant shortening. Six nails were removed due to irritation by locking screws. These results are comparable with those of larger series in the literature with other types of interlocking nails. The union rate in this series was 97.5%.     

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.     

Interlocking intramedullary nail with reaming of bone marrow cavity in treatment of tibia and femur pseudarthrosis]

The aim of this paper was to assess the results of treatment of pesudoarthrosis of the tibia and femur with reamed interlocked intramedullary nailing. A group of 17 patients with pseudoarthrosis of long bones were treated. Pseudoarthrosis were located in 10 cases in the tibia and in 7 cases in the femur. In the analysed group there were 14 male and 3 female patients (average age: 48 years). All patients were treated by locked intramedullary nailing. Complete bone union was observed in 15 cases, 1 case is still under observation (radiological signs of bone union are already evident) and in 1 case treatment failed to resolve the pseudoarthrosis. Intramedullary interlocking nailing in the treatment of long bone pseudoarthrosis give very good stability and creates very good conditions for blood vessel penetration between the bone fragments. The reaming procedure yields biologically active material that accelerates the bone union process.     

Intramedullary nailing of distal metaphyseal tibial fractures

BACKGROUND: The treatment of distal metaphyseal tibial fractures remains controversial. This study was performed to evaluate the results of intramedullary nailing of distal tibial fractures located within 5 cm of the ankle joint. METHODS: Over a sixteen-month period at two institutions, thirty-six tibial fractures that involved the distal 5 cm of the tibia were treated with reamed intramedullary nailing with use of either two or three distal interlocking screws. Ten fractures with articular extension were treated with supplementary screw fixation prior to the intramedullary nailing. Radiographs were reviewed to determine the immediate and final alignments and fracture-healing. The Short Form-36 (SF-36) and Musculoskeletal Function Assessment (MFA) questionnaires were used to evaluate functional outcome. RESULTS: Acceptable radiographic alignment, defined as <5 degrees of angulation in any plane, was obtained in thirty-three patients (92%). No patient had any change in alignment between the immediate postoperative and the final radiographic evaluation. Complications included one deep infection and one iatrogenic fracture at the time of the intramedullary nailing. Six patients could not be followed. The remaining thirty fractures united at an average of 23.5 weeks. Three patients with associated traumatic bone loss underwent a staged autograft procedure, and they had fracture-healing at an average of 44.3 weeks. The functional outcome was determined at a minimum of one year for nineteen patients and at a minimum of two years (average, 4.5 years) for fifteen patients. At one year, there were significant limitations in several domains despite fracture union and maintenance of alignment, but there was improvement in the MFA scores with time. CONCLUSIONS: Intramedullary nailing is an effective alternative for the treatment of distal metaphyseal tibial fractures. Simple articular extension of the fracture is not a contraindication to intramedullary fixation. Functional outcomes improve with time.     

Graded exchange reaming and nailing of non-unions

The effect of graded exchange reaming and intramedullary nailing on a non-union model in the rat femur was studied by clinical, radiological, bone mineralisation and biomechanical methods. A standardised procedure was first developed to create a non-union that did not heal and in which non-union developed consistently. In 30 male Wistar rats a standardised osteotomy was produced in the left femur diaphysis. The fractures were reamed to 1.5 mm and nailed with a soft polyethylene nail for 12 weeks. After 1 week the fractures were manipulated in bending and rotation every 2nd day for 5 weeks. At 12 weeks radiographs demonstrated a hypertrophic non-union in all fractures, and the rats were randomly divided into three groups. In the control group no reoperation was performed (group C). In group 1.6 exchange reaming to 1.6 mm and medullary nailing were performed, and reaming and nailing to 2.0 mm in group 2.0. The effect of extensive versus modest reaming and nailing on bone repair was then assessed 12 weeks later. Physical examination, radiographs, bone mineralisation measurements by dual energy X-ray absorptiometry (DEXA) and biomechanical femures evaluated by a three-point bending test in a Mini Bionix (MTS) testing system were employed. In the control group radiographs revealed a state of non-union in all fractures, and the mechanical strength was significantly reduced compared with both intervention groups. Bone mineral content (BMC) and bone mineral density (BMD) were reduced in the callus region compared with group 2.0. In the intervention groups radiographs showed various degrees of union. Mechanical testing showed that the fracture energy was significantly higher in group 2.0 than in group 1.6. The finding that extensive exchange reaming and nailing seems favourable in non-unions of diaphyseal fractures compared with modest reaming may have clinical implications. Received: 18 December 1997