Clinical orthopaedics and related research
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Clin. Orthop. Relat. Res. · Aug 2005
ReviewLocal antibiotic delivery vehicles in the treatment of musculoskeletal infection.
The primary benefit achieved with local antibiotic delivery vehicles is the ability to obtain extremely high levels of local antibiotics without increasing systemic toxicity. Antibiotic-loaded bone cement represents the current standard as an antibiotic delivery vehicle in orthopaedic surgery. Biodegradable alternatives to antibiotic-loaded bone cement also are being used clinically and there are many new products in the active stages of development. ⋯ Composite biomaterials that simultaneously provide the functions of variable antibiotic delivery patterns and also contribute to the process of bone regeneration represent the most ideal class of local antibiotic delivery vehicles. High concentrations of certain antibiotics have been shown to affect the process of normal bone regeneration adversely in a dose dependent response. Considerable investigation still is required to determine the proper use of locally administered antibiotics to negotiate the balance between eradicating infection without excessively inhibiting the processes of bone regeneration.
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Clin. Orthop. Relat. Res. · Aug 2005
Comparative StudyLateral malleolus en bloc resection and ankle reconstruction for malignant tumors.
Four children and six adults required en bloc resection of the lateral malleolus for malignant tumors. There were four osteosarcomas, three chondrosarcomas, two Ewing's sarcomas, and one adamantinoma. Surgical margins were wide in seven patients, marginal in two, and intralesional in one. A primary ankle arthrodesis was done in four adults and bracing without any reconstruction was done in four children and two adults. During a mean followup of 14.5 years (range, 3-30 years), there were two local recurrences (two of 10 patients) after a marginal excision and an intralesional excision. One patient had reoperation for a skip osteosarcoma lesion in the proximal fibula. Other complications included chronic osteomyelitis, a lateral talus subluxation and cavovarus deformity, and recurrent ankle instability and degenerative changes of the ankle. At the latest followup, all 10 patients showed no evidence of disease. Five patients who had primary or late ankle arthrodesis had a Musculoskeletal Tumor Society and International Society of Limb Salvage functional score of 28 points (92%), and two adolescents who had postoperative bracing alone had a functional score of 24 points (80%). The three remaining patients had a salvage amputation. ⋯ Therapeutic study, Level IV (case series--no, or historical control group). See the Guidelines for Authors for a complete description of levels of evidence.
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Surgeons continually struggle to reduce orthopaedic infections, but no current treatment offers minimum side effects with maximum effectiveness. Antibiotics mixed in plaster of paris have been successful in treating large bony defects in patients with chronic osteomyelitis, and have the advantage of being well tolerated and absorbed by the body. Antibiotics impregnated in polymethylmethacrylate (PMMA) have offered local antibiotic delivery with some success. ⋯ In vitro studies have shown promising results of antibiotic elution from bioabsorbable microspheres and beads. Animal in vivo tests have shown that antibiotic impregnated polymers can successfully treat induced osteomyelitis in rabbits and dogs. These studies have provided consistent reproducible results, and now it is time to plan human trials to assess the efficacy of antibiotic microspheres implanted in infected bone and to plan in vivo and in vitro animal testing to investigate the feasibility of antibiotic-polymer-coated components.
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Clin. Orthop. Relat. Res. · Aug 2005
Comparative StudyThe biceps squeeze test for diagnosis of distal biceps tendon ruptures.
Using the Thompson test for Achilles tendon rupture as a model, we developed the biceps squeeze test to test the integrity of the distal biceps tendon. We wanted to determine if failure to elicit supination with the biceps squeeze test would indicate complete distal biceps rupture. We also wanted to determine if surgical reattachment of the tendon would reestablish the supination response of the biceps squeeze test, and if patients who did not have surgery would have the same response to the biceps squeeze test months after injury. Twenty-five consecutive patients with 26 presumptive distal biceps tendon ruptures were evaluated with the biceps squeeze test. The biceps squeeze test was positive in 24 patients. Twenty-two patients had surgical repair. Twenty-one of 22 patients had operative confirmation of a complete distal biceps tendon rupture. All patients who had surgery had return of supination with the biceps squeeze test immediately after reattachment and at 3 months followup. Two patients with a positive biceps squeeze test declined surgery and did not have a return of supination with the biceps squeeze test at 3 months followup. Sixty-five patients with no history of upper extremity trauma were evaluated with the biceps squeeze test as a control group. All 65 patients had supination of the forearm in response to the test. The biceps squeeze test is simple, reliable, cost-effective, and aids in the diagnosis of distal biceps tendon ruptures. ⋯ Diagnostic study, Level II-1 (development of diagnostic criteria on basis of consecutive patients-with universally applied reference "gold" standard). See the Guidelines for Authors for a complete description of levels of evidence.
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Clin. Orthop. Relat. Res. · Aug 2005
Comparative StudyMotor points for neuromuscular blockade of the adductor muscle group.
We sought to identify the motor nerve points for the adductor muscle group, relate them to specific surface anatomy markings, and define the points in terms of percentage distances along an anatomic reference line. We dissected four muscles in each of 20 legs from 15 skeletally mature, formalin-preserved cadavers. ⋯ The mean motor points and 95% confidence limits were as follows: adductor longus, 31% +/- 1.1%; adductor brevis, 22% +/- 1.8%; adductor magnus, 38% +/- 2.5%; and gracilis, 44% +/- 3.1%. Identification of these motor points facilitates accurate placement of neuromuscular blocking agents, such as botulinum toxin, and may lead to increased clinical efficacy of the block with a reduction in local or systemic side effects.