Delayed and non-union of the humeral diaphysis--compression plate or internal plate fixator?

Open Reduction and Internal Fixation for Humeral Shaft Nonunion: Bone Grafting Is Not Routinely Required and Avoids Donor Site Morbidity

OBJECTIVES

To document union rate, complications and patient-reported outcomes after open reduction and internal fixation (ORIF), with and without bone grafting (BG), for humeral diaphyseal nonunion after failed nonoperative management.

DESIGN

Retrospective.

SETTING

University teaching hospital.

PATIENTS AND INTERVENTION

From 2008 to 2017, 86 consecutive patients [mean age 59 years (range 17-86), 71% (n = 61/86) women] underwent nonunion ORIF (plate and screws) at a mean of 7 months postinjury (range 3-21.5). Eleven (13%) underwent supplementary BG.

MAIN OUTCOME MEASUREMENTS

Union rate and complications for 83 patients (97%) at a mean of 10 months (3-61). Patient-reported outcomes (QuickDASH, EQ-5D, EQ-VAS, SF-12, satisfaction) for 53 living, cognitively-intact patients (78%) at a mean of 4.9 years (0.3-9.2).

RESULTS

Ninety-three percent (n = 77/83) achieved union after nonunion ORIF. Complications included recalcitrant nonunion (7%, n = 6/83), iatrogenic radial nerve palsy (6%, n = 5/83), infection (superficial 7%, n = 6/83; deep 2%, n = 2/83), and iliac crest donor site morbidity (38%, n = 3/8). The union rate with BG was 78% (n = 7/9) and without was 95% (n = 70/74; P = 0.125), and was not associated with the nonunion type (atrophic 91%, n = 53/58; hypertrophic 96%, n = 24/25; P = 0.663). Median QuickDASH was 22.7 (0-95), EQ-5D 0.710 (-0.181-1), EQ-visual analog scale 80 (10-100), SF-12 physical component summary 41.9 (16-60.5), and mental component summary 52.6 (18.7-67.7). Nineteen percent (n = 10/53) were dissatisfied with their outcome.

CONCLUSIONS

ORIF for humeral diaphyseal nonunion was associated with a high rate of union. Routine BG was not required and avoided the risk of donor site morbidity. One in 5 patients were dissatisfied despite the majority achieving union.

LEVEL OF EVIDENCE

Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.

Revision with Locking Compression Plate by Compression Technique for Diaphyseal Nonunions of the Femur and the Tibia: A Retrospective Study of 54 Cases

Nonunion after diaphyseal fracture of the femur or the tibia is a common but difficult complication for treatment. Currently, the main treatment modalities include nail dynamization, exchange nailing, and bone transport, but revision with compression plating in these nonunions was rarely reported. To evaluate the outcomes of compression plating in the treatment of femur and tibia shaft nonunions, we retrospectively reviewed 54 patients with diaphyseal nonunion of the tibia or the femur treated with locking compression plate (LCP) by compression technique. There were 46 aseptic and 8 septic nonunions in the case series. Patient's history, fracture characteristics, previous interventions, and types of nonunion were recorded. The possible reason which might lead to nonunion was also analyzed for each case. Patients with aseptic nonunions were revised by hardware removal and compression plating with or without bone grafting. For septic nonunions, a two-stage surgery strategy was used. Compression plating with iliac crest bone grafting (ICBG) or free vascularized fibular grafting (FVFG) was used as the final treatment for septic nonunions. The compression technique and bone grafting method were individualized in each case according to the patient's history and architecture of the nonunion. Each patient finished at least a two-year follow-up, and all cases achieved healing uneventfully. Our study showed that compression plating with LCP was an effective method to treat diaphyseal nonunions of the tibia and the femur. It is compatible with different bone grafting methods for both infected and noninfected nonunions and is a good alternative to the current treatment methods for these nonunions.

Healing the Index Humeral Shaft Nonunion: Risk Factors for Development of a Recalcitrant Nonunion in 125 Patients

BACKGROUND

Humeral shaft nonunions are challenging to treat, and those that require >1 surgical procedure in order for a nonunion to heal are termed recalcitrant. Most studies on nonunion have evaluated the union rate independent of the number of procedures required to achieve union. The aims of the present study were (1) to compare the healing rates after the index operation for the treatment of a nonunion with conventional versus locked plating with or without graft augmentation, (2) to report the prevalence of recalcitrant nonunion, and (3) to identify risk factors that predict a recalcitrant nonunion.

METHODS

We performed a retrospective analysis of a prospectively collected database of 125 humeral shaft nonunions treated with open reduction and plate fixation by a single surgeon over 25 years. Univariate and multivariate regression analyses were performed to compare healing rates by type of plate fixation and biological augmentation and to identify demographic, injury, and treatment-related risk factors for the development of a recalcitrant nonunion.

RESULTS

One hundred and five patients (84%) had healing after the index procedure for the treatment of nonunion. Twenty patients (16.0%) required secondary procedures and were defined as having a recalcitrant nonunion. Eight of these patients (6.4% of the overall group) healed after the secondary interventions, and 12 (9.6% of the overall group) had a failure to unite. There were no significant differences in healing rates between conventional and locked plates or between the types of bone graft (autogenous or recombinant human bone morphogenetic protein). Risk factors for the development of a recalcitrant nonunion were plate fixation of the acute humeral fracture, a history of deep infection, and ≥2 prior procedures.

CONCLUSIONS

Plate fixation with bone graft augmentation remains a successful method for the treatment of humeral shaft nonunions. Neither plate type nor graft type reduced the risk of a recalcitrant nonunion. Factors that predicted a recalcitrant nonunion were operative fixation of the acute fracture with a plate, a history of deep infection, and ≥2 surgical procedures.

LEVEL OF EVIDENCE

Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.

Lateral Subcutaneous Locking Compression Plate and Small Incision Reduction for Distal-third Diaphyseal Humerus Fractures

Objective

Iatrogenic radial nerve injury is a great challenge for orthopaedic surgeons who deal with distal‐third diaphyseal humerus fractures. Conventional open reduction and internal fixation (ORIF) remains the gold standard, but complications such as nonunion and iatrogenic radial nerve injury still occur. We fixed the fractures with a lateral locking compression plate (LCP) subcutaneously after small incision reduction to protect the radial nerve. This study reports the clinical and radiographic outcomes of our modified method.

Methods

Thirty‐eight patients with distal‐third diaphyseal humerus fractures were treated with lateral subcutaneous LCP and small incision reduction at our department between September 2013 and August 2016. There were 33 males and 5 females, with an average age of 30.3 years (range, 17 to 49 years). All the cases were types A or B (AO/OTA classification, type A, 24 cases; type B, 14 cases). Among them, 6 cases were combined with preoperative radial nerve palsy. All patients were diagnosed with closed humeral fractures after X‐ray examination, and had typical upper limb pain, swelling, and movement disorders. The operations were performed by a single surgeons’ team. Union time, range of motion (ROM), University of California, Los Angeles (UCLA) shoulder rating scale, and Mayo Elbow Performance Index (MEPI) scores were assessed to evaluate the postoperative results.

Results

All patients were followed up for an average of 11.4 months (range, 3 to 36 months). The average operation time was 75.5 min (range, 60 to 150 min) and average intraoperative radiation exposure was 10.5 s (range, 8 to 18 s). Bony union was achieved in all cases after an average of 16.2 weeks (range, 12 to 25 weeks). No complications such as infection or screw and plate fracture occurred, and no iatrogenic radial nerve injury was observed. According to the UCLA shoulder rating scale, the average score was 33.7 (range, 31 to 35), with 33 excellent (86.8%) and 5 good cases (13.2%). They were all excellent according to their MEPI scores (ranging, 94 to 100, with an average of 97.4). The average operation time for secondary removal of the plate was 15.2 min (range, 10 to 20 min), and no complications such as infection or secondary radial nerve injury occurred.

Conclusions

Lateral subcutaneous LCP and small incision reduction may reduce the risk of iatrogenic radial nerve injury significantly in the treatment of distal‐third diaphyseal humerus fractures. It also leads to solid fixation, good postoperative function, and convenient removal of the plate without injuring the radial nerve.

Outcomes of distal humerus diaphyseal injuries fixed with a single-column anatomic plate

PURPOSE

The locking compression extra-articular distal humerus plate (EADHP) is an anatomically shaped, angular stable single-column fixation system for distal third humerus fractures. The purpose of this retrospective study was to evaluate clinical and radiographic outcomes after open reduction and internal fixation of distal humerus fractures with this device.

METHODS

Twenty-one consecutive patients with distal humerus fractures were treated with the EADHP system between February 2006 and June 2012. Of these, 19 were clinically and radiographically evaluated after a mean follow-up of 10.4 months. Follow-up assessment included anteroposterior and lateral radiographs, assessment of range of motion (ROM), pain according to a visual analogue scale (VAS) and Disabilities of the Arm, Shoulder and Hand (DASH) score.

RESULTS

All fractures demonstrated satisfactory reduction and healing at an average of 7.3 months. One patient showed post-operative sensory ulnar neuropathy that recovered completely, and nine patients had a preoperative radial nerve palsy, which recovered spontaneously following exploration and plating. Mean post-operative ROM was as follows: flexion 126°, extension -7°, pronation 82° and supination 83°. The VAS score was zero points in eight patients, while the mean DASH score was 25.8 points.

CONCLUSIONS

For extra-articular distal humerus fractures, including high-energy injuries often seen in gunshot wounds or motor vehicle injuries, the anatomically shaped angular stable single-column plate provides satisfactory clinical and radiographic results and serves as a valuable tool in the treatment of these injuries.

Plating, nailing, external fixation, and fibular strut grafting for non-union of humeral shaft fractures

PURPOSE

To compare various treatment modalities (plating, Ilizarov external fixation, and non-vascular fibular cortical strut grafting) for non-union of humeral shaft fractures.

METHODS

Records of 9 women and 26 men aged 24 to 71 (mean, 42) years who presented with non-union of humeral shaft fractures were reviewed. The humeral shaft fractures were secondary to low-energy trauma (n=22) or vehicular accidents (n=13) and involved the proximal (n=9), middle (n=15), and distal (n=11) regions. 13 of the fractures were open. Infection was evident in 8 of the non-unions. For non-unions with infection (n=8), a 2-stage procedure entailing temporary Ilizarov fixation followed by plating was used. For non-unions without infection (n=23), one-stage plating and cancellous bone grafting was used. For non-unions of osteoporotic bone (n=4), one-stage non-vascularised fibular strut grafting was used. Outcome was measured using the Disabilities of the Arm, Shoulder and Hand (DASH) scoring system.

RESULTS

The 35 patients were followed up for a mean of 16 (range, 6-60) months. All achieved bone union except for one (who had persistent infection). Respectively for non-unions with infection, nonunions without infection, and non-unions of osteoporotic bone, the mean times to bone union were 6.5 (range, 4-10), 5 (range, 4-8), and 10 (range, 6-14) months, the mean improvement in DASH score was 30, 43, and 18, and malalignment was noted in 5, 2, and one patient. Three patients had a preoperative radial nerve palsy for which standard tendon transfer was performed 6 weeks after treatment for non-union.

CONCLUSION

Compression plating achieved the best results. An external fixator may be used temporarily for infected non-unions. Fibular strut grafting may be used when non-unions warrant additional stability.

Intermittent administration of human parathyroid hormone before osteosynthesis stimulates cancellous bone union in ovariectomized rats

It has been reported that intermittent administration of human parathyroid hormone (h-PTH) promotes bone healing after surgery for osteoporotic fractures. If bone healing is promoted by the administration of h-PTH during pre-operative waiting period, we can prevent prolonged bed rest. Therefore, we evaluated the effects of pre-operative h-PTH treatment on cancellous bone union and its mechanism for fracture healing in ovariectomized rats as a model for osteoporosis. Ovariectomized 7-month-old female Sprague-Dawley rats underwent an osteotomy of the proximal tibia as a fracture model, and h-PTH (30 μg/kg body weight) or vehicle was administered as a pre-operative treatment for one week. After the one-week treatment, tibiae were fixed with wire for osteosynthesis, and h-PTH or vehicle was administered for 1 or 3 weeks following wire fixation. In addition to bone histomorphometry, we used alcian blue/hematoxylin stained sections for evaluating cartilage volume and immunostained sections for analyzing the expression of proliferating cell nuclear antigen (PCNA) for cell proliferation and that of Sox9 and Runx2, differentiation markers for cartilage cells and osteoblasts, respectively. Pre-operative treatment with PTH significantly increased bone volume. Pre-operative and pre- to post-operative treatment with PTH for 2 weeks significantly promoted bone union. Pre-operative treatment with PTH significantly increased cartilage volume, and pre- to post-operative treatment with PTH for 2 weeks significantly increased the percentage of cells positive for Runx2 (p < 0.01), but not PCNA or Sox9. Pre-operative administration of h-PTH enhances bone union by promoting cartilage formation and cell differentiation to osteoblasts, but not by promoting cell proliferation.

Biomechanical considerations for surgical stabilization of osteoporotic fractures

The incidence of osteoporotic fractures has been steadily rising along with the aging of the population. Surgical management of these fractures can be a challenge to orthopedic surgeons. Diminished bone mass and frequent comminution make fixation difficult. Advancements in implant design and fixation techniques have served to address these challenges and when properly applied, can improve overall outcome. The purpose of this review is to describe fixation challenges of common osteoporotic fractures and provide options for successful treatment.

Treatment of aseptic nonunion after intramedullary nailing fixation with locking plate

OBJECTIVE

To evaluate the safety and efficacy of locking plate combined with bone grafting in the treatment of aseptic nonunion following intramedullary nailing fixation of fractures of the long bones.

METHODS

Thirty-eight consecutive patients treated in our hospital between January 2004 and December 2006 were included in this retrospective study. The nonunions included 20 femurs, 15 tibias, and 3 humeri. The duration of non-union ranged from 6 to 84 months and 21 (55.3%) of them were located around the metaphysis of the affected long bones. There were 12 women and 26 men with a mean age of 39.2 years (range, 9-70 years). Locking plate combined with bone grafting was the procedure chosen to treat every case of nonunion in this series. The clinical outcomes were evaluated.

RESULTS

All patients were followed up for 6-20 months (average 11.6 months). After locking plate fixation combined with bone grafting, union was achieved in all cases, the average healing time being 5.3 months (range, 4-8 months). Infection of the superficial incision occurred in three cases (7.9%) and delayed healing of the incision in one case, all of which healed with no further complications. The function of the adjacent joints was excellent to good in 30 patients (78.9%), fair in 7 (18.4%) and poor in 1 (2.6%) after follow-up.

CONCLUSION

Locking plate fixation combined with bone grafting is a highly effective treatment for aseptic nonunions of the long bones after intramedullary nailing fixation, especially in the case of metaphyseal nonunion.

Judet decortication and compression plate fixation of long bone non-union: Is bone graft necessary?

Non-union occurs in 5-10% of all fractures and is caused by a variety of mechanical and biological factors. Stable fixation is essential and many authors recommend the addition of bone graft. Our aim was to evaluate the results of internal fixation using Judet decortication and compression plating for long bone fractures and assess the impact of bone grafting on union rates. Our study group comprised all the patients undergoing compression plate fixation under a single surgeon over a fourteen year period (n=96). AO principles were used and the standard technique involved Judet decortication, compression plating and lag screws. Autologous bone graft was harvested from the iliac crest. The mean age was 45 years and 62% were male. The fracture site was the clavicle (n=20); humerus (n=23); radius and ulna (n=5); femur (n=31) and tibia (n=17). The primary fracture treatment was non-operative (n=41); IM nail (n=22); plate fixation (n=28) and external fixation (n=5). Deep infection was present in 6 cases. Bone graft was used in 40 cases. 91/96 non-unions treated with compression plating healed (95%). Bone grafting was used in all cases for the initial part of the series but its use declined as the surgeon became more confident that the non-unions would heal without the use of bone graft. The case mix and complexity remained constant throughout the study period and the union rate also remained constant. The mean time to radiological union was 6.4 months. In those treated with a compression plate without bone graft the union rate was 94.6% whilst the addition of bone graft resulted in a union rate of 95% (p=0.67). From our study we concluded that the routine use of autologous bone graft may not be necessary and, based upon the union rates observed in this study, a prospective randomised study to evaluate the use of bone graft in non-union surgery would need a sample size of 194,000 to detect a significant increase in union with 80% power. In terms of Numbers Needed Treat (NNT), we would need to give 1179 patients a bone graft to prevent one additional failure of healing.

Screw locking elements: a means to modify the flexibility of osteoporotic fracture fixation with DCPs without compromising system strength or stability

This paper analyses whether it is possible to use dynamic compression plates (DCPs) and screw locking elements (SLEs) to vary the flexibility of osteoporotic fracture fixation without compromising the strength and stability of the construct. Compression, torsion and four-point bending static strength tests were conducted. Cyclic load tests of up to 10,000 load cycles were also carried out to determine stiffness performance. Four fixation systems were mounted onto polyurethane bone models. Group 1 consists of the DCP and six cortical screws. Group 2, idem, but with the addition of two SLEs. Group 3, idem, but with the addition of six SLEs. Group 4 used the locking compression plate (LCP) and locking screws. The results indicated no significant difference (p>0.05) in the strength of groups 2-4. It was also observed that the torsional stiffness of group 3 (0.30 Nm/°) was higher than that of group 2 (0.23 Nm/°) and similar to that of group 4 (0.28 Nm/°). Compression stiffness of group 4 (124 N/mm) was higher than that of group 2 (102 N/mm), but lower than that of group 3 (150 N/mm). No notable differences were observed for structural bending stiffness. It is concluded that by using the DCP with SLEs it is possible to modify the stiffness of the fixation construct for the repair of osteoporotic fractures and, in this way, facilitate the conditions suitable on secondary bone healing.

Locked plate fixation of osteoporotic humeral shaft fractures: are two locking screws per segment enough?

OBJECTIVE

The purpose of this study was to compare the biomechanical behavior of using two versus three locking screws per bone segment in a cadaveric humerus fracture gap model.

METHODS

Six matched pairs of elderly osteoporotic fresh-frozen human cadaveric humerii were used. An eight-hole locking compression plate was placed posteriorly on the humeral shaft and secured with either four or six bicortical locking screws. A 5-mm middiaphyseal gap osteotomy was created to simulate a comminuted fracture without bony contact. Specimens were tested in offset axial compression, four-point anteroposterior bending, four-point medial-lateral bending, and torsion. After the initial testing in each of these modalities, the constructs were cyclically loaded in torsion and again tested in the four loading modalities. Lastly, the fixation constructs were then tested to failure in torsion.

RESULTS

There were no significant differences in stiffness between the group fixed with two screws per segment and the group fixed with three screws per segment. The peak torque to failure was higher in the four-screw construct compared with the six-screw construct. The mean torque to failure was 23.5 +/- 3.7 Nm in the construct with two locking screws per segment compared with 20.4 +/- 2.8 Nm in the construct with three locking screws per segment (P = 0.030).

CONCLUSIONS

The addition of a third screw in the locked plate construct did not add to the mechanical stability in axial loading, bending, or torsion. In testing to failure, the addition of a third screw resulted in lower load to failure.

Two-plate fixation for humeral shaft non-unions

PURPOSE. To review 22 patients who underwent 2-plate fixation for non-union of the humeral shaft. METHODS. 13 women and 9 men aged 32 to 76 (mean, 48) years underwent fixation for non-union of the humeral shaft, using a 2-plate construct, together with decortication, debridement, and bone grafting. The two 3.5-mm reconstruction plates were parallel and lying at 90 degrees to each other and fixed with screws purchasing into at least 6 cortices of each fragment for both plates. Fractures were located in the upper third (n=8) or middle third (n=14) of the humerus. Initial treatments included casting (n=9), coaptation splinting (n=8), multiple retrograde pinning (n=4), and Marchetti-Vicenzi nailing (n=1). 18 non-unions were atrophic and 4 were hypertrophic. Shoulder and elbow range of motion as well as functional results were evaluated. RESULTS. The time for union was 4.6 (range, 4-6) months. No implants were loose or broken. No nonunion or infection was noted. Functional results were excellent in 17 and good in 5 patients. One patient had iatrogenic radial nerve palsy that recovered within 3 months. CONCLUSION. Two-plate fixation achieves good results for humeral shaft non-unions.

Intermittent administration of human parathyroid hormone enhances bone formation and union at the site of cancellous bone osteotomy in normal and ovariectomized rats

Intermittent administration of human parathyroid hormone (hPTH) has an anabolic effect on bone in animals and humans and is expected to be a potent agent for the treatment of osteoporosis. However, little is known about the effects of hPTH on cancellous bone healing after cancellous bone fractures or osteotomies. We evaluated whether hPTH enhanced bone union at the site of cancellous bone osteotomy and further elucidated the possible mechanisms of hPTH effects on cancellous bone healing. After a bilateral ovariectomy (OVX) or sham operation in mature female rats, cancellous bone osteotomy was performed on the right proximal tibia. After once-a-week administration of hPTH (1-34) (100 microg/kg) or its vehicle for 4 weeks, bilateral tibiae including osteotomy and non-osteotomy sites were harvested. Along with conventional bone histomorphometry, cancellous bone union at the osteotomy site and the rate of proliferating cells immunostained with proliferating cell nuclear antigen (PCNA) and adipocytes in the surrounding bone marrow were evaluated. hPTH increased cancellous bone volume by stimulating bone formation in both normal and OVX rats and suppressed adipocyte volume (p<0.05). The percentage of PCNA-positive cells at the osteotomy site after PTH treatment was 2- to 3-fold higher than that of vehicle treatment controls both in sham-operated and OVX rats (p<0.05). The magnitude of increase in the percentage of PCNA-positive cells after PTH treatment at the osteotomy site was two times higher than that at the non-osteotomy site. Furthermore, PTH treatment increased cancellous bone union after osteotomy both in sham-operated and OVX rats (p<0.05). These results suggest that hPTH enhances cancellous bone healing at the site of osteotomy with, at least in part, a local regulating action that increases osteoblastogenesis and decreases adipocytogenesis at and around the osteotomy.

Ilizarov frame fixation without bone graft for atrophic humeral shaft nonunion: 28 patients with a minimum 2-year follow-up

OBJECTIVES

To evaluate the outcomes of patients with atrophic humeral shaft nonunion (HSNU) treated by Ilizarov frame fixation without the use of bone graft.

DESIGN

A retrospective review of 28 consecutive patients treated in 1 center between 1996 and 2002.

SETTING

Tertiary referral center.

PATIENTS AND METHODS

We studied 28 consecutive patients: 12 male and 16 female. Of the patients, 21 had been previously operated (15 by internal fixation using compression plates, 3 by intramedullary nailing, and 3 by external fixation), and 9 of those 21 patients also had failed revision procedures; 7 patients had been treated nonoperatively from the time of injury to the time of the index procedure for HSNU. Mean age at the time of the index operation was 44 years (16-73 years).

INTERVENTION

Removal of the previous fixation device, excision of fibrous tissue at the HSNU site, opening of the intramedullary canal, excision of avascular bony ends, and stabilization fixation and compression of the humerus with an Ilizarov circular frame (proximal semicircular ring) using smooth 1.8-mm K-wires. No bone graft was used. The mean postoperative follow-up was 76 months (24-174 months).

MAIN OUTCOME MEASUREMENTS

Radiologic union using plain radiographs. Clinical and functional outcome using the Lammens system, which evaluates pain, range of shoulder and elbow movements (and their limitations), and humeral alignment and union. Patient subjective outcomes were assessed using a 4-point patient satisfaction questionnaire.

RESULTS

Bony union was achieved in all 28 cases after a mean of 4.1 months (3.4-5.7 months). There were 6 superficial pin tract infections (which resolved with antibiotics) and 1 transient radial nerve palsy (which resolved at 2.5 months). One patient refractured his humeral shaft following a fall, but the fracture successfully united 5.7 months later after a further Ilizarov frame application. All patients had good or excellent functional outcomes and range of shoulder and elbow movements as rated by the Lammens scoring system.

CONCLUSIONS

Ilizarov circular frame fixation without bone graft is a reliable method for the treatment of atrophic nonunion of the humerus, even after failed previous surgery.

Biomechanical considerations in plate osteosynthesis: the effect of plate-to-bone compression with and without angular screw stability

OBJECTIVE

We compared the biomechanical stability of bone-plate constructs using a compression plate (CP), an internal fixator (IF), and a combination plate (CP/IF).

METHODS

Standardized simulated shaft fractures with a segmental defect in composite bones (n=60) and intraarticular distal femur fractures with a comminuted supracondylar zone in fresh frozen cadaveric femurs (n=36) were stabilized by CP, IF, and CP/IF. Construct stiffness, plastic deformation, and fixation strength were measured under axial compression and torsion using a biaxial testing machine.

RESULTS

The experimental results indicate for the distal femur fracture model that IF has less loss of reduction by plastic deformation under axial load compared to CP (IF 61% of CP). Under torsion, the CP showed significantly (P<0.05) decreased plastic deformation compared to the IF (CP 51% of IF). The combination (CP/IF) of the 2 fixation principles generally resulted in a higher load to failure under axial compression and torsion (145% failure load of CP and 118% of IF under axial compression, 88% of CP and 109% of IF under torsion). Results were similar between the 2 fracture models.

CONCLUSIONS

Under compression, IF provides similar fixation in comminuted fractures and was better than the CP for avoiding loss of reduction, whereas under torsional loading, CP was more important for stiffness, plastic deformation, and load to failure than IF. However, combination (CP/IF) fixation seems advisable in intraarticular and extraarticular fractures of long bones with a metaphyseal comminution. These data may be utilized by surgeons to build a more specific treatment plan in patients with these fracture types.

Locking versus standard plates for allograft fixation after tumor resection in children and adolescents

PURPOSE

This investigation was undertaken to assess the performance of locking plates in comparison to standard compression plates for allograft fixation after resection of malignant primary skeletal tumors.

METHODS

Using a computerized database, patients younger than 18 years who had undergone resection of malignant skeletal tumors with allograft reconstruction from January 1998 through June 2004 were identified. Demographic, oncological, surgical, and follow-up data were collected, and comparison of outcomes with regard to allograft-host junction healing between locking and standard compression plates was undertaken.

RESULTS

Thirty-nine patients meeting the inclusion criteria were identified. Homogeneity of the study group with regards to age, sex, diagnosis, adjuvant therapy, and presence of metastases allowed for evaluation of allograft-host union as a relatively independent variable. Nine patients in the locking plate group (75%) united after the index procedure at an average of 13.1 months. Fifteen patients (55.6%) with compression plates healed after the initial reconstruction at an average of 14.6 months. Complications and secondary procedures were noted.

CONCLUSIONS

Results of this investigation suggest that use of locking plates for allograft-host junction fixation is associated with improved union rates and less need for additional operations when compared with standard compression plates.

Principles of fixation of osteoporotic fractures

Despite advances in the prevention and treatment of osteoporotic fractures, their prevalence continues to increase. Their operative treatment remains a challenge for the surgeon, often with unpredictable outcomes. This review highlights the current aspects of management of these fractures and focuses on advances in implant design and surgical technique.

Humeral shaft fractures treated by dynamic compression plates, Ender nails and interlocking nails

Between January 1991 and December 2002, we treated 92 acute, displaced, closed humeral shaft fractures (AO classification type A). We used three fixation methods: dynamic compression plates (DCP) in 36 patients, Ender nails (EN) in 32 patients and interlocking nails (ILN) in 24 patients. The patients were followed for a minimum of 24 months. At one year, all fractures except two (one DCP/one ILN) had united. Patients treated with EN had shorter mean operation time, 51 (35-110) min; less mean blood loss, 70 (30-170) ml and shorter mean hospital stay, 5.8 (3-12) days. There were three iatrogenic radial nerve palsies: two in the DCP group and one in the ILN group. There was one wound infection. There were three cases with impingement of the shoulder but range of motion was restored after nail removal. For patients with multiple trauma or high operative risk, EN fixation served as a safer and faster procedure. ILN fixation offered a stable fixation via a smaller incision but more fracture comminution might happen.