Trochanteric flip osteotomy for cranial extension and muscle protection in acetabular fracture fixation using a Kocher-Langenbeck approach.

OBJECTIVE: To describe the advantages and surgical technique of a trochanteric flip osteotomy in combination with a Kocher-Langenbeck approach for the treatment of selected acetabular fractures. DESIGN: Consecutive series, teaching hospital. METHODS: Through mobilization of the vastus lateralis muscle, a slice of the greater trochanter with the attached gluteus medius muscle can be flipped anteriorly. The gluteus minimus muscle can then be easily mobilized, giving free access to the posterosuperior and superior acetabular wall area. Damage to the abductor muscles by vigorous retraction can be avoided, potentially resulting in less ectopic ossification. Ten consecutive cases of acetabular fractures treated with this approach are reported. In eight cases, an anatomic reduction was achieved; in the remaining two cases with severe comminution, the reduction was within one to three millimeters. The trochanteric fragment was fixed with two 3.5-millimeter cortical screws. RESULTS: All osteotomies healed in anatomic position within six to eight weeks postoperatively. Abductor strength was symmetric in eight patients and mildly reduced in two patients. Heterotopic ossification was limited to Brooker classes 1 and 2 without functional impairment at an average follow-up of twenty months. No femoral head necrosis was observed. CONCLUSION: This technique allows better visualization, more accurate reduction, and easier fixation of cranial acetabular fragments. Cranial migration of the greater trochanter after fixation with two screws is unlikely to occur because of the distal pull of the vastus lateralis muscle, balancing the cranial pull of the gluteus medius muscle.

Use of muscle cells to mediate gene transfer to the bone defect.

Segmental bone defects and nonunions are relatively common problems facing all orthopaedic surgeons. Osteogenic proteins, i.e., BMP-2, can promote bone healing in segmental bone defects. However, a large quantity of the human recombinant protein is needed to enhance the bone healing potential. Cell mediated gene therapy in the bone defect can allow a sustained expression of the osteogenic proteins and further enhance bone healing. Muscle cells can be easily isolated and cultivated, and they are known to be an efficient gene delivery vehicle to muscle and nonmuscle tissues. Furthermore, they are capable of transforming into osteoblasts when stimulated by BMP-2. Thus, the utilization of muscle cells as the gene delivery vehicle to a bone defect would be an important step in establishing a less invasive treatment for non-unions and segmental bone defects. Muscle cells were transduced when the adenoviral-lacZ vector and injected into the bone defect and the muscles surrounding the defect. Expression of the marker gene was visualized 7 days after the injection, both macroscopically and microscopically, using lacZ histochemistry. The lacZ expressing cells in the defect tissue were also stained for desmin, a muscle specific marker, indicating the presence of muscle cells that have fused into myofibers in this nonmuscle bone defect area. With successful myoblast mediated gene delivery into the segmental bone defect, future experiments would focus on delivering viral vectors expressing osteogenic proteins to eventually improve bone healing postinjury.

Biomechanical, radiologic, and histopathologic correlations in the pathogenesis of experimental intervertebral disc disease.

STUDY DESIGN: The desert sand rat, an animal model for spinal degenerative disc disease, was studied for biomechanical, histologic, and radiographic characteristics. Load deformation curves with peak force and force decay, hematoxylin-eosin-stained sections, and lateral radiographs were correlated. OBJECTIVES: The hypothesis that the subchondral bone response preceded or contributed to the degenerative disc disease seen in the desert sand rat was tested. SUMMARY OF BACKGROUND DATA: Intervertebral disc disease spontaneously develops in the desert sand rat during its lifetime. Approximately 50% will have significant disc disease by age 18 months. Previous studies have found metabolic and histologic changes associated with intervertebral disc degeneration in the sand rat. METHODS: Desert sand rats were killed at 3-, 9-, 15-, and 18-month intervals and tested in Rheometrics Solid Analyzer with nondestructive step strain loading to obtain a load deformation curve. Radiographs and histologic sections of each animal were compared. Peak force and force decay were analyzed by level and by age. Analysis of variance and Tukey's methods were applied to data. RESULTS: There were no statistically significant differences in biomechanical data. No histologic changes were noted in the study groups up to 18 months of age. Radiographic differences characterized by subchondral bony sclerosis were noted by 18 months of age. No trends were noted when radiographic grades were compared with force data. CONCLUSIONS: The absence of biomechanical histologic changes in the intervertebral disc per se from 3 through 18 months, with radiographic changes in the subchondral bone, supports the hypothesis that the earliest changes in intervertebral disc disease in this animal model are related to the subchondral bone response.

Iliosacral screw fixation of the posterior pelvic ring using local anaesthesia and computerised tomography.

Various techniques have been used for the fixation of the posterior pelvis, each with disadvantages specific to the technique. In this study, a new protocol involving the placement of posterior pelvic screws in the CT suite is described and evaluated. A total of 66 patients with unstable pelvic ring injuries was stabilised under local anaesthesia with sedation. The mean length of time for the procedure was 26 minutes per screw. There were no technical difficulties or misplaced screws and no cases of infection or nonunion. All patients stated that they would choose to have the CT scan procedure again rather than a procedure requiring general anaesthesia. The charges for the procedure were approximately 1840 pounds sterling (2800 dollars) per operation. CT-guided placement of iliosacral screws is a safe, feasible, and cost-effective alternative to radiologically-guided placement in the operating theatre in selected patients.

Human skeletal muscle cells in ex vivo gene therapy to deliver bone morphogenetic protein-2.

We have examined whether primary human muscle-derived cells can be used in ex vivo gene therapy to deliver BMP-2 and to produce bone in vivo. Two in vitro experiments and one in vivo experiment were used to determine the osteocompetence and BMP-2 secretion capacity of cells isolated from human skeletal muscle. We isolated five different populations of primary muscle cells from human skeletal muscle in three patients. In the first in vitro experiment, production of alkaline phosphatase by the cells in response to stimulation by rhBMP-2 was measured and used as an indicator of cellular osteocompetence. In the second, secretion of BMP-2 was measured after the cell populations had been transduced by an adenovirus encoding for BMP-2. In the in vivo experiment, the cells were cotransduced with a retrovirus encoding for a nuclear localised beta-galactosidase gene and an adenovirus encoding for BMP-2. The cotransduced cells were then injected into the hind limbs of severe combined immune-deficient (SCID) mice and analysed radiographically and histologically. The nuclear localised beta-galactosidase gene allowed identification of the injected cells in histological specimens. In the first in vitro experiment, the five different cell populations all responded to in vitro stimulation of rhBMP-2 by producing higher levels of alkaline phosphatase when compared with non-stimulated cells. In the second, the five different cell populations were all successfully transduced by an adenovirus to express and secrete BMP-2. The cells secreted between 444 and 2551 ng of BMP-2 over three days. In the in vivo experiment, injection of the transduced cells into the hind-limb musculature of SCID mice resulted in the formation of ectopic bone at 1, 2, 3 and 4 weeks after injection. Retroviral labelling of the cell nuclei showed labelled human muscle-derived cells occupying locations of osteoblasts in the ectopic bone, further supporting their osteocompetence. Cells from human skeletal muscle, because of their availability to orthopaedic surgeons, their osteocompetence, and their ability to express BMP-2 after genetic engineering, are an attractive cell population for use in BMP-2 gene therapy approaches.

Medial malleolar osteotomy for exposure of complex talar body fractures.

Traditional surgical approaches to the talus often fail to afford adequate exposure of the talar body, especially in the case of complex talar body fractures. Preservation of the remaining blood supply to the talus is a main concern during operative repair and can be difficult to accomplish when multiple approaches and forceful manipulations are required to gain satisfactory exposure. A medial malleolar osteotomy was used to gain access to the talar body in situations in which the traditional approaches did not provide adequate exposure. We describe our technique in a small series of patients.

Trochanteric flip osteotomy for cranial extension and muscle protection in acetabular fracture fixation using a Kocher-Langenbeck approach.

OBJECTIVE: To describe the advantages and surgical technique of a trochanteric flip osteotomy in combination with a Kocher-Langenbeck approach for the treatment of selected acetabular fractures. DESIGN: Consecutive series, teaching hospital. METHODS: Through mobilization of the vastus lateralis muscle, a slice of the greater trochanter with the attached gluteus medius muscle can be flipped anteriorly. The gluteus minimus muscle can then be easily mobilized, giving free access to the posterosuperior and superior acetabular wall area. Damage to the abductor muscles by vigorous retraction can be avoided, potentially resulting in less ectopic ossification. Ten consecutive cases of acetabular fractures treated with this approach are reported. In eight cases, an anatomic reduction was achieved; in the remaining two cases with severe comminution, the reduction was within one to three millimeters. The trochanteric fragment was fixed with two 3.5-millimeter cortical screws. RESULTS: All osteotomies healed in anatomic position within six to eight weeks postoperatively. Abductor strength was symmetric in eight patients and mildly reduced in two patients. Heterotopic ossification was limited to Brooker classes 1 and 2 without functional impairment at an average follow-up of twenty months. No femoral head necrosis was observed. CONCLUSION: This technique allows better visualization, more accurate reduction, and easier fixation of cranial acetabular fragments. Cranial migration of the greater trochanter after fixation with two screws is unlikely to occur because of the distal pull of the vastus lateralis muscle, balancing the cranial pull of the gluteus medius muscle.

Monoarticular acromioclavicular joint gout: a case report.

Acromioclavicular joint gout is extremely rare. The case presented represents the first case of monoarticular acromioclavicular joint gout reported. It is also the first reported case of acromioclavicular joint gout in an immunosuppressed patient. The diagnostic pitfalls inherent in the evaluation of acute monoarticular arthritis in an immunosuppressed patient are illustrated. Furthermore, the case demonstrates one of the atypical presentations of gout that may occur in renal transplant patients taking cyclosporin A.

Efficacy of contained metaphyseal and periarticular defects treated with two different demineralized bone matrix allografts.

The efficacies of two different allografts, Grafton (demineralized bone matrix [DBM] in a glycerol carrier) and Orthoblast (DBM in a reverse thermal poloxamer carrier) were examined from cases involving periarticular fractures. Demographic, perioperative, and outcome data for patients with periarticular fractures who underwent a prospectively designed protocol for bone grafting were compiled, with 15 cases using Orthoblast and 13 using Grafton. A successful graft was defined as healing on the first graft attempt without complications. Healing was determined by radiographic studies and clinical evaluation. The successful graft rates of Orthoblast and Grafton were 15/15 and 9/13, respectively.

Femoral nailing with transverse locking screws through the femoral neck.

We treated 55 patients with subtrochanteric or comminuted femoral fractures with a transverse locking femoral nail (Alta, Howmedica). This nail was positioned more cephalad than usual so that at least one fixation screw was located in the femoral neck or head. Forty-seven fractures (20 subtrochanteric and 27 diaphyseal) were available for follow-up averaging 12 months (3-35). The time to radiographic healing averaged 7 months (3-21). There was one delayed union, one non-union, two superficial infections, one broken proximal screw, one compartment syndrome of the thigh, and one peroneal nerve palsy. There were no femoral neck fractures, avascular changes of the femoral head, or gluteal irritation at the most recent follow up. The described technique appears safe and effective, is technically easy, and avoids intra-articular screws.

Lateral and anterior plating of intra-articular distal femoral fractures treated via an anterior approach.

Thirty-five patients with 36 displaced distal femoral fractures (16 AO-type C2 and 19 AO-type C3) were treated with an anterior approach and double plating and followed for an average of 7 (3-44) months. Bone grafting with allograft and demineralized bone matrix was used. Postoperative therapy included immediate ROM and non-weight bearing for 12 weeks. Two patients died during hospitalization and one was lost to follow-up. Reductions were near anatomic in all but three patients. Uneventful healing by 16 weeks occurred in 24/36 fractures. Double plating via the anterolateral approach minimized stripping of the medial side and improved controlled access to the distal femur.

Primary retroperitoneal sarcomas: common symptoms, common diagnoses, uncommon disease.

Primary retroperitoneal sarcomas may present with symptoms and signs that mimic common musculoskeletal disorders of the extremities that are quite remote from the source of the problem. This often misleads the clinician and results in delays in diagnosis. The authors present 6 patients with retroperitoneal sarcoma who had a common or nonspecific orthopaedic condition of the extremity. Delays in diagnosis ranged from 2 to 30 months. No patient survived his or her tumor. Clinicians should be alerted to the possibility of a retroperitoneal tumor that presents primarily or initially with extremity signs and symptoms but with few or no clues of the presence of a localized sarcoma in the retroperitoneal space.

Pin reduction and fixation of volar fracture fragments of distal radius fractures via the flexor carpi radialis tendon.

BACKGROUND: The objective of this study was to evaluate a technique for reduction and stabilization of residually displaced volar fragments in intraarticular distal radius fractures. METHODS: A consecutive series of patients with AO type C3 distal radius fractures treated by one surgeon were studied. Percutaneously placed pins were placed through the flexor carpi radialis tendon to reduce and stabilize volar fracture fragments of distal radius fractures when closed reduction was unsuccessful. The goal of treatment was to achieve less than 2 mm of articular congruity. Postoperative physiotherapy was protocol-based. A validated outcome measurement was used to evaluate patients. RESULTS: Of 117 patients, 10 met the inclusion criteria. In all patients, a successful reduction of the volar fragment was achieved with less than 2 mm of residual articular step-off. Reduction was maintained in 8 patients. Follow-up averaged 29 months, and there were no complications associated with the technique. All patients were satisfied with the treatment. CONCLUSION: Although the final outcome of patients with this type of fracture depends on many factors, in the small series of patients described, a satisfactory reduction was possible using the describe technique. Transtendinous pinning is a new, undescribed technique that is useful in the treatment of such specific injuries.

Knee function after patellectomy and cruciform repair of the extensor mechanism.

When patellectomy is performed, the objectives should include restoration of a moment arm, centralization of the extensor mechanism, adequate range of motion, and cosmesis. The cruciate repair of the extensor mechanism described in this report has been developed to meet the aforementioned objectives. Eight patients with 12 patellectomies described herein were examined with Cybex testing of the knee at a follow-up period of 18 months to 20 years (mean, 56 months). A four-quadrant tissue dissection of the patellar soft-tissue enclosure was reconstructed in a cruciform pants-over-vest fashion, with the superomedial flap containing the vastus medialis insertion on top. This "soft-tissue" patella attempts to provide a greater moment arm than simpler repairs. This study examines whether this construct restored the torque of extension while concomitantly facilitating centralization of the extensor mechanism. Cybex testing of both knees examined both extensor and flexor function with specific regard to the ratio of extensor to flexor forces. Patients with patellectomies had few subjective complaints, with a mean knee score of 94 (median, 100). The extensor torque was not completely restored and there was a moderate decrease in the quadriceps function, both subjectively and objectively as measured by Cybex testing. The authors also found that in patients with unilateral patellectomies, the ratios of extension to flexion function, a parameter not yet reported in the literature, were significantly different between the normal and patellectomized knees. The same extension to flexion ratios were seen in patients with bilateral patellectomies. Because patients with patellar pathology requiring patellectomy frequently have chronic and bilateral disease, comparative functional evaluation may be difficult.(ABSTRACT TRUNCATED AT 250 WORDS)

Growth disturbances after injuries of the proximal tibial epiphysis.

Proximal tibial epiphyseal fractures are very rare. Partial growth arrest of the physis can cause important axial malalignment in the frontal or the sagittal plane or both, with subsequent shift of the weight-bearing axis onto the injured compartment of the knee joint. To detect the exact extent of the deformity, comparative radiographs of the contralateral side in two planes using long films as well as standing whole leg orthoradiographs are desirable. Accurate measurements in our series of six patients revealed deformities in two, which required secondary surgical correction.

Modified transverse locking nail fixation of proximal femoral fractures.

It was hypothesized that transverse locking screws of intramedullary nails, seated above the lesser trochanter, provide equal strength to that of reconstruction nails, and that screws placed through the medial cortex of the femoral neck do not have adverse biomechanical effects during physiologic loading. Synthetic femurs (n = 10) and paired anatomic specimen femurs (n = 14) were tested intact and with an intramedullary device in place. Intact specimens were loaded nondestructively, then a segmental subtrochanteric defect was created and either a high seated transverse locking nail or a reconstruction nail was inserted and statistically locked. Axial and torsional stiffness were determined followed by axial failure testing. Mechanical parameters evaluated were stiffness, displacement, and energy. The implanted specimens did not show any statistically significant difference between transverse or reconstruction screw constructs with any of the measured parameters (stiffness, displacement, and energy). Failure tests in implanted specimens also did not show any statistically significant difference in yield load, yield displacement, or energy to failure between implant constructs. All anatomic specimens failed, with fractures of the proximal fragment involving medial and lateral cortices. Synthetic specimens did not fracture but showed failure with implant deformation at the level of the skeletal defect. The use of high seated transverse locking nails for complex proximal femoral fractures is a viable option and has comparable in vitro mechanical performance with reconstruction nails. Although not shown to be a problem in the present study, clinical evaluation of screws through the medial femoral neck cortex is required.

The impact of the quantity of skeletal injury on mortality and pulmonary morbidity.

OBJECTIVE: To determine if the quantity of skeletal injuries (and the timing to fixation) increases the mortality or pulmonary morbidity in patients with and without chest injuries. DESIGN: Retrospective analysis of trauma registry. Statistical analysis with multiple logistic regression and chi(2) analysis. METHODS: Looking specifically at adult patients (> 16 years), skeletal injury was quantified by determining the presence or absence of a fracture in specific body regions (humeri, forearm, femur, tibia, spine, and pelvis) for a maximum of 10 skeletal injuries. The timing of fixation for fractures was categorized as < 24 hours, < 48 hours, < 72 hours, < 5 days, > 5 days, or no fixation. Chest injuries and pulmonary morbidity were based on the accepted list of complications reported in the literature. RESULTS: Three groups were analyzed according to the presence or absence of a chest or skeletal injury: those without skeletal injury (group NSI, n = 59), those without chest injuries (group NCI, n = 108), and those with both skeletal and chest injuries (group B, n = 59) Pulmonary Complications: When all patient groups (NCI, NSI, and B) were pooled, greater chest injury (p < 0.0008), greater skeletal injury (p < 0.02), and delayed fixation (p < 0.04) were associated with increased risk of developing a pulmonary complication. In the group of patients without a chest injury (NCI), this risk was associated with greater head injury (p < 0.005) and greater skeletal injury (p < 0.04), whereas in the group without a skeletal injury (NSI), only chest injury demonstrated significance (p < 0.05). When both skeletal and chest injuries were present, greater head injury (p < 0.03) and fixation time (p < 0.03) increased the risk of developing a pulmonary complication. Mortality: With all patients pooled (NCI, B, and NSI), head injury (p < 0.02), abdominal injury (p < 0.012), and fixation time (p < 0.01) were risk factors. In patients without a chest injury (NCI), none of the indexed variables were associated with mortality. In patients without a skeletal injury (NSI), greater head injury (p < 0.01), greater chest injury (p < 0.01), and greater abdominal injury (p < 0.04) were risk factors for mortality. When both chest and skeletal injuries were present (B), only head injury (p < 0.0003) was associated with mortality. The prevalence of mortality and pulmonary complications were compared between groups NCI, NSI, and B. Group NCI had fewer pulmonary complications (p < 0.004) than the other groups (difference not significant). When examining mortality, group NCI had less mortality than groups NSI and B. CONCLUSION: The combination of skeletal and chest injuries does not seem to amplify the pulmonary morbidity and mortality compared with chest injury alone. The quantity of the skeletal injury and the time to fixation of structures affecting mobilization seem to have an effect on pulmonary morbidity and mortality. Better scientific studies on the effects of skeletal injury and timing to fixation in relation to pulmonary morbidity and mortality are required.

Relapsing polychondritis and spondyloarthropathies.

We report 3 patients with polychondritis who also developed spondyloarthropathy: one B27 negative patient with ankylosing spondylitis (AS) who also exhibited uveitis and optic neuritis; a B27 positive patient with AS who developed acute aortic insufficiency and Crohn's disease; and a B27 negative patient with Reiter's syndrome. The possible association of spondyloarthropathy with relapsing polychondritis is discussed.