Nonunion after a tibial shaft fracture complicating tibial tubercule osteotomy

Tibial shaft fracture after tibial tubercle osteotomy in total knee replacement is a rare complication. We report on a 67-year-old man who had a knee revision arthroplasty in which a long tubercle osteotomy was performed to facilitate exposure. Three weeks after surgery, he presented with a transverse shaft fracture, which became a nonunion requiring surgical management. This shaft nonunion and its solution after tibial tubercle osteotomy is discussed as well as relevant literature.     

The use of the Zuelzer hook plate in fixation of olecranon fractures

A method using ethylenediaminetetraacetate (EDTA) and toluene-treated pea bacteroid suspensions for the acetylene reduction assay is described. The high level of acetylene reduction by these bacteroids is comparable to that of intact plants. Reproducibility of the EDTA-toluene treatment is, on the average, within 5%. Preliminary experiments with soybeans indicate that the EDTA-toluene method might be applicable to other legumes as well.     

Patella height after high tibial osteotomy with internal fixation and early motion

The purpose of this study was to compare the incidence of patella infera in patients after high tibial osteotomy treated with either postoperative immobilization or internal fixation and early range of motion. A retrospective review of 98 patients with high tibial osteotomy was done at the authors' institution. Thirty-three patients who had secondary procedures such as concomitant ligamentous reconstruction with early motion were excluded. Therefore, 69 knees in 65 patients remained in the study cohort. Group A consisted of 32 patients (34 knees) treated with postoperative immobilization, whereas Group B included 33 patients (35 knees) treated with internal fixation and early motion. The preoperative and postoperative Insall-Salvati index, Blackburne-Peel index, and angular alignment were determined for each group. Between Groups A and B, the differences in the Insall-Salvati index and the Blackburne-Peel index were statistically significant, although the difference in angular correction was not significant. With rigid fixation and early motion the Insall-Salvati index showed that there was less postoperative shortening of the patellar tendon. The relationship of the patella to the remainder of the knee was affected less adversely as evidenced by the Blackburne-Peel index. High tibial osteotomy with internal fixation and early range of motion should result in a better knee and ease the subsequent performance of a total knee arthroplasty.     

Metallic or absorbable fracture fixation devices. A cost minimization analysis

Absorbable polyester pins and screws for the internal fixation of small fragment fractures have been commercially available for several years. The main advantage of these devices is that no implant removal procedures are required, which could result in financial savings. The current cost analysis, which included costs of medical care plus costs of lost time from work, was based on 994 fracture patients treated with absorbable internal fixation devices and 1173 patients operated on using conventional metallic devices. The fracture types studied were uni- and trimalleolar fractures of the ankle, fractures of the olecranon, and metacarpal fractures. When the costs for an implant removal procedure after metallic fixation were included, the average cost saved per patient by using absorbable implants varied from $410 in fractures of the olecranon to $903 in unimalleolar fractures. However, hardware removals often are optional. According to the results of this cost analysis, the break even point is attained at a removal rate of 19% for metacarpal fractures, 21% for unimalleolar fractures, 46% for fractures of the olecranon, and 54% for trimalleolar fractures. Only at a higher removal rate would the use of absorbable devices, with their current prices, be a financially more favorable alternative than the use of metallic ones.     

Chance fracture after pedicle screw fixation. A case report

STUDY DESIGN: A case of a Chance fracture through an instrumented pedicle is presented. The radiographic and intraoperative findings and management of this complication are reported. OBJECTIVE: To increase awareness of the complications of transpedicular screw fixation and to suggest a form of management of this unusual complication. SUMMARY OF BACKGROUND DATA: To the authors' knowledge, this is the first reported case of such a vertebral fracture occurring after pedicle screw fixation. METHODS: A 44-year-old man with athetoid cerebral palsy and a progressive thoracic kyphosis sustained a Chance fracture at the caudal end of the segmental instrumentation construct. RESULTS: Surgical intervention, including fracture reduction and extension of the instrumented fusion to the pelvis, provided effective restoration of physiologic sagittal alignment. CONCLUSION: Chance fracture after pedicle screw fixation can be successfully managed with surgical intervention.     

Stress fracture of the fifth metatarsal after Evans' calcaneal osteotomy: a report of two cases

The Evans calcaneal lengthening osteotomy has gained popularity in recent years for the treatment of symptomatic flexible pes planus deformity. To our knowledge, the occurrence of a stress fracture of the fifth metatarsal has not been reported after this procedure. We report two such cases and discuss the probable mechanism of this problem, a relative overloading of the lateral aspect of the foot. Both cases were treated successfully with immobilization. Clinicians should be aware of this possible problem and treat it appropriately.     

Stability of maxilla downgrafting after rigid or wire fixation

PURPOSE: This article compares the long-term outcomes of rigid internal fixation with wire fixation. PATIENTS AND METHODS: In this retrospective study, nine cases of vertical midface augmentation in which rigid fixation was used were compared with 11 cases with wire fixation. One surgeon completed all cases for the rigid fixation group, and another surgeon completed the cases in the wire fixation group. RESULTS: Follow-up was 16 +/- 11 months for the rigid fixation group and 20 +/- 12 months for the wire fixation group. Inferior movement at the anterior portion of the maxilla was 7.0 +/- 2.9 mm with rigid fixation and 4.5 +/- 3.6 mm with wire fixation (P < .05). Postsurgical superior movement (relapse) was 0.4 +/- 0.4 mm with rigid fixation and 2.4 +/- 2.4 mm with wire fixation (P < .01). Inferior movement at the posterior maxilla was 3.1 +/- 0.2 mm with rigid fixation and 2.8 +/- 2.3 mm with wire fixation. Postsurgical superior movement (relapse) was 0.8 +/- 0.4 mm with rigid fixation and 0.5 +/- 2.3 mm with wire fixation, which was not significantly different. CONCLUSION: This comparison showed downgrafting of the maxilla using autogenous bone harvested from the iliac crest and rigid internal fixation to be a predictable and stable procedure.     

Stress fracture of the tibia after arthrodesis of the ankle or the hindfoot

We studied twelve patients who had a stress fracture of the tibia and one patient who had a stress fracture of the fibula after arthrodesis of the ankle or the foot. A second stress fracture subsequently developed in two patients. All but two patients were managed non-operatively, and the fractures healed uneventfully. One patient who was managed operatively had a below-the-knee amputation to treat a painful non-union of a tibial fracture, and the other had interlocking intramedullary nailing for a displaced fracture. All but one of the arthrodesis sites had fused before the stress fracture occurred. All of the stress fractures that occurred after arthrodesis of the ankle were in the middle and distal aspects or the distal aspect of the tibia, while those that occurred after triple arthrodesis were in the distal aspect of the fibula or the medial malleolus. Although six of the thirteen patients still had uncorrected alignment and deformity after the arthrodesis, optimum alignment after the arthrodesis did not preclude the occurrence of a stress fracture. We conclude that stress fracture must be considered in the differential diagnosis of pain months or even years after solid fusion at the site of an ankle or triple arthrodesis.     

Revision total knee arthroplasty after failed unicompartmental knee arthroplasty or high tibial osteotomy

A retrospective matched-pair comparative analysis was done between 30 total knee arthroplasties following failed high tibial osteotomies and 30 total knee arthroplasties following failed unicompartmental knee arthroplasties. The groups were matched according to age, gender, type of prosthesis, primary disease, and length of followup. A minimum followup of 2 years was required for inclusion in the study, and the average followup was 3.8 years (range, 2-9 years). The Knee Society Knee Score for the high tibial osteotomy group was significantly higher than that for the unicompartmental arthroplasty group. More osseous reconstructions were required in the unicompartmental revisions. Difficulty with exposure was not significantly greater in the osteotomy group. Rates of component loosening were not significantly different between the groups. A failed unicompartmental knee arthroplasty and a failed high tibial osteotomy can be revised successfully to a total knee arthroplasty. The results confirm that revisions after unicondylar arthroplasty and high tibial osteotomy are technically demanding. In this series, the results of total knee arthroplasty following unicompartmental knee arthroplasty approached but did not equal those obtained after high tibial osteotomy.     

Biodegradable interlocking nails for fracture fixation

Serious problems such as stress shielding, allergic reactions, and corrosion are associated with the use of metallic fracture fixation devices in fractured long bones. Metal implants often are removed during a second retrieval operation after fracture healing has completed. A biocompatible implant that degrades slowly during implantation would obviate the need for a second operation and save the patient from considerable physical, psychologic, and financial discomfort. The biodegradable implant must provide the fractured limb sufficient support for a certain time, allowing early loading. A gradual transfer of load from the biodegradable implant to the bone would result in a better product of bone healing and avoid stress shielding. In an animal model using adult sheep, two types of biodegradable polymer interlocking nails were tested in comparison with a stainless steel interlocking nail. Fracture healing, mechanical properties of the bones, degradation behavior in vivo and in vitro, and tissue response were monitored during a 2 1/2-year followup study. To detect shifts in acid base relations caused by the release of acid compounds, pH measurements were performed. Fracture healing was unimpaired, and the mechanical test results of all three groups were excellent. Histologic analysis showed a mild inflammatory response, but no pH shifts were observed. The results of this study justify additional research on these promising materials.     

Postoperative stability after sagittal split ramus osteotomy with condylar-positioning appliance and screw fixation: asymmetric versus symmetric cases

BACKGROUND AND OBJECTIVE: Myelodysplastic syndrome progenitor cells can be grown and expanded in long term bone marrow liquid cultures in the presence of multiple cytokines. In this study we investigated the pattern of differentiation and response to growth factors in six cases of myelodysplastic syndrome (MDS) with well-defined cytogenetic abnormalities by means of conventional cytogenetics and fluorescence in situ hybridization (FISH). METHODS: Bone marrow cells were grown in stroma-free liquid cultures in the presence of SCF, IL-3, IL-6 and GM-CSF. RESULTS: IN three cases a CFU-GM expansion comparable to normal controls was observed, together with a decrease or increase of cells with abnormal karyotype. Two cases showed no response to growth factor stimulation, morphological signs of terminal myeloid differentiation and increase (one case) or decrease (one case) in the percentage of abnormal FISH signals along the cultures. In one additional case, while CFU-C expansion was present, clearcut leukemic transformation was observed in the culture, together with a sharp decrease in the percentage of abnormal FISH signals, indicating a leukemic transformation of MDS progenitor cells with a normal karyotype. INTERPRETATION AND CONCLUSIONS: Our data indicate that FISH analysis is generally a poor indicator of clonality in MDS; nevertheless, determining the kinetics of cytogenetically abnormal clones in liquid bone marrow cultures may provide insight as to the growth abnormalities of MDS progenitor cells and may be useful prior to in vivo growth factor administration.     

Instrumentation and techniques in equine fracture fixation

In recent years fracture fixation in the horse has changed significantly. New devices, mainly adapted from the human field, have been successfully introduced into large animal surgery. Examples of such implants include the DCS/DHS implant system, the self-tapping screw, the cannulated screw, and the pinless external fixator. However, new devices have also been developed exclusively for equine fracture management, including the interlocking intramedullary nail and the external skeletal fixation device. With these devices the surgeon has more options for repairing fractures in horses. Nevertheless, many problems are still unsolved. Indications exist that during the next few years new, exciting fracture fixation systems will be developed, providing further advancements in the quest for the ideal implant for horses. However, the development stages of these devices are such that mentioning the possibilities here is premature.     

Skeletal stability and relapse patterns after Le Fort I osteotomy using miniplate fixation in patients with isolated cleft palate

We present a series of 14 consecutive isolated cleft palate patients aged 17 to 25 years (mean 19 years) who underwent Le Fort I maxillary advancement fixed with miniplates by the senior author (Posnick) over the period 1987-1991. Ten of the patients underwent autogenous bone grafting; all were stabilized intraoperatively with four miniplates, a prefabricated acrylic splint, and intermaxillary fixation. The patients were analyzed to determine amount and timing of horizontal and anterior and posterior vertical relapse, correlation between advancement and relapse, effect of a pharyngoplasty in place at time of osteotomy, effect of performing multiple jaw procedures, and maintenance of overjet and overbite. Tracings of preoperative and serial postoperative lateral cephalograms (immediate, 6 to 8 weeks, and 1 year) were analyzed to calculate horizontal and vertical maxillary changes and the amount of overjet and overbite maintained. Clinical follow-up ranged from 1.5 to 5.5 years (mean 2.5 years). No significant difference was seen in vertical or horizontal change or relapse between patients who had maxillary surgery alone (n = 10) and those who had operations in both jaws (n = 4), nor did outcome vary significantly for those who had a pharyngoplasty in place (n = 8) at the time of their Le Fort I osteotomy. The mean "effective" maxillary advancement for the group was 6.4 mm, with 5.4 mm maintained 1 year later (mean relapse 1.0 mm).(ABSTRACT TRUNCATED AT 250 WORDS)     

Monitoring fracture site properties with external fixation

An in-vitro system has been devised to monitor the properties of an idealized fracture site immobilized with a Hoffman-Vidal external fixator. A dial gage was used to measure the relative pin displacements under controlled axial loading. The displacement measurements were then used in conjunction with a finite element model to predict the modulus of an idealized fracture site. Five fracture sites made of neoprene disks of different mechanical properties were monitored in order to simulate the increasing modulus of a healing fracture. Good agreement was observed between directly measured mechanical properties of the neoprene and those inferred from the combined finite element and pin displacement tests.     

Biomechanical comparison of intramedullary and percutaneous pin fixation for proximal humeral fracture fixation

BACKGROUND: The G6PD deficiency is a red cell enzymopathy very frequent in certain Mediterranean countries. In Menorca (Balearic Islands), a relatively high incidence of favism carried us to study the prevalence of this alteration, taking advantage of the "Campaign for detection of heterozygous beta-thalassaemia to prevent the homozygous beta-thalassaemia" that we make annually. METHODS: We studied a total of 1139 school boys between 13-14 years old for three consecutive school years. We used the methylene blue as screening test and the deficiency of G6PD was confirmed with enzymatic quantification in the haemolysate. We also analysed the clinical manifestations and studied the relatives. RESULTS: We have confirmed 11 cases of G6PD deficiency (prevalence of 9.7/1000), all of them native of the island. The clinical manifestations were: in 6 cases (54.5%) no clinical manifestations were found, 5 cases (45.4%) had presented neonatal jaundice and 2 cases (18.2%) had suffered a favism crisis. The study of relatives permitted us to analyse 26 additional samples (17 women and 9 men), detecting in 8 of them (4 women and 4 men) the enzymopathy . CONCLUSIONS: The prevalence of G6PD deficiency in Menorca is one of the highest in Spain. Most of the carriers are asymptomatic, the most important clinical manifestations being the neonatal jaundice and favism. The screening test used is efficient for unmistakable hemizygotes detection.     

A mechanical comparison of subtrochanteric femur fracture fixation

The aim of this study was to compare in vitro diagnostic performance of three electrical methods for occlusal caries diagnosis with that of visual inspection and bite-wing radiography. One hundred and seven extracted molar and premolar teeth were subjected to the diagnostic methods by 2 operators and subsequently sectioned for histological validation. Electrical measurements were made at site level and at surface level using two different instruments. The diagnostic parameters calculated from the results were: sensitivity, specificity, diagnostic accuracy at a theoretical caries prevalence of 10% and area under the ROC curve. The electrical methods and bite-wing radiography showed higher sensitivity and lower specificity than visual inspection. Diagnostic accuracy was significantly lower for bite-wing radiography and one electrical method than for visual inspection. Overall diagnostic performance of two electrical methods was superior.     

Comparison between the rigidity of bicortical screws and a miniplate for fixation of a mandibular setback after a simulated bilateral sagittal split osteotomy

PURPOSE: This investigation compared the biomechanical stability of three bicortical screws with that of a single four-hole miniplate after 5-mm mandibular setback after a bilateral sagittal split osteotomy (BSSO) in cadaver mandibles. MATERIALS AND METHODS: Thirty human cadaver hemimandibles underwent BSSO followed by two different rigid fixation techniques. All specimens had no third molar, bony pathology, or evidence of mandibular fracture, and there was no history of renal disease or hyperparathyroidism. The specimens were randomly divided into two groups. In group I, three bicortical screws were placed at the superior border, and in group II, one four-hole miniplate was secured on the external oblique ridge with four monocortical screws. The bony height of the mandible was recorded. Maximum resistance load (MRL), the greatest load recorded just before a sudden decrease in load level (bone or fixation failure), was recorded when the mandibles were tested in a compression machine. Multiple regression analysis was used to evaluate the differences in bone height and the MRL between groups I and II. RESULTS: The mean bone height in groups I and II were 28.64 +/- 2.50 mm and 28.72 +/- 4.08 mm, respectively. The mean MRL in group I (20.49 +/- 7.22 kg) was greater than in group II (17.41 +/- 7.81 kg). The multiple regression analysis showed no significant difference in the bone height and the MRL between group I and group II (beta = 2.3492, P = .4114). CONCLUSION: There was no statistically significant difference in stability provided the two techniques.