The influence of profession on functional ankle stability in musicians.

OBJECTIVE: The aim of this study was to examine the influence of extensive work-related use of the feet on functional ankle stability among musicians. METHODS: Thirty professional organists were compared to professional pianists and controls. All participants completed a questionnaire. Range of motion (ROM), peroneal reaction time, and positional sense tests of the ankle were measured. The postural balance control was investigated with the Biodex Stability System for the stable level 8 and unstable level 2. Statistical analysis was done with the Kruskal-Wallis test, Mann-Whitney test with Bonferroni-Holm correction, and Fisher's exact test. RESULTS: Nine of 30 organists compared to 5 of 30 pianists and controls reported ankle sprains in their medical history. Pianists had a significant increased flexion of both ankle joints compared to organists (p < 0.01) and increased flexion of the right ankle joint compared to controls (p = 0.02). The positional sense test and postural balance control showed no significant differences among groups. The peroneal reaction time of the right peroneus longus muscle was significantly increased in pianists compared to controls (p = 0.008). CONCLUSIONS: Organists have shown a high incidence of ankle sprains. Despite their extensive work-related use of the ankle joints, organists have neither increased functional ankle stability nor increased ROM of their ankle joints in comparison to controls. Pianists have increased flexion of the ankle joint, perhaps due to the exclusive motion of extension and flexion while using the pedals. To minimize injuries of the ankle and improve functional ankle stability as well as balance control, proprioceptive exercises of the ankle in daily training programs are recommended.

Fracture models in the lumbar sheep spine: a biomechanical investigation.

The purpose of this study was to find out if a limited resection of the cranial vertebral body leaving the posterior wall intact is a sufficient model for AO type 3 fractures, or if additional resection of the posterior wall is necessary. In six, fresh-frozen, lumbar sheep spine specimens, the segmental stability was tested in three motion planes in a spine tester. First, the intact specimens were tested. Then, partial resection of the intervertebral disc L3/4 and resection of the cranial vertebral body of L4 was performed, leaving the posterior wall intact. This defect was tested without instrumentation and with a ventral monosegmental interlocking plate mounted. Then, the defect was extended to a total cranial resection, including the posterior wall, and the tests were subsequently repeated. The stability of both types of defects under the different conditions was compared. Without instrumentation, the total cranial resection showed significantly more ROM in flexion/extension and axial rotation than partial cranial resection. With the ventral interlocking plate mounted, the instability in total cranial resection was significantly higher in flexion/extension, with the relative relation even being increased. In axial rotation and lateral bending, the differences were equalized by the mounted plate. From a biomechanical point of view, total cranial resection including the posterior wall should be preferred as a sheep spine fracture model for AO type 3 fractures.

Anatomic Reconstruction of Malunited Chopart Joint Injuries.

Fractures and dislocations at the mid-tarsal (Chopart) joint are frequently overlooked or misinterpreted at first presentation. Inadequate joint reduction and stabilization almost invariably lead to painful malunions or nonunions, residual instability, and deformity. Because of the central position and the essential function of the mid-tarsal joint, malunions lead to a considerable impairment of global foot function and the rapid development of posttraumatic arthritis. While secondary anatomical reconstruction with joint preservation would be desirable in order to restore normal foot function, it is amenable only if no symptomatic arthritis or avascular necrosis is present. Over a course of 6 years, eight patients have been treated with secondary correction, joint realignment, and internal fixation. In four of these cases, nonunions of the tarsal navicular were debrided and bone-grafted; in the remaining cases, a corrective osteotomy at the navicular or cuboid was carried out. At 2 years followup, all but one patient were satisfied with the result. One patient underwent fusion of the talonavicular joint for avascular necrosis and collapse of the navicular. The mean American Orthopaedic Foot and Ankle Score (AOFAS) improved significantly from 38.8 preoperatively to 80.8 at follow-up. However, the majority of malunited mid-tarsal fracture-dislocations will require corrective fusion of the affected joint(s) with axial realignment because of manifest posttraumatic arthritis at the time of patient presentation.

High union rates and function scores at midterm followup with ankle arthrodesis using a four screw technique.

UNLABELLED: When evaluating the role of ankle arthrodesis in the treatment of severe ankle arthritis, postoperative infection, nonunion, and the development of arthritis at the adjacent joints are major issues when considering treatment alternatives. We evaluated the rate of complications, the functional outcome, and compensatory range of motion at the midtarsal joint at medium-term followup after ankle arthrodesis with four cancellous screws. We performed 94 ankle fusions in 92 patients; 12 patients were lost to followup and eight declined to participate, leaving 72 patients (76%) for evaluation. The minimum followup was 4.8 years (mean, 5.9; range, 4.8-7.8 years). No patient developed a deep infection; three patients developed postoperative hematoma which we operatively drained. Union occurred in 93 of the 94 patients (99%). The sagittal motion at the midtarsal joint averaged 24 degrees . Secondary arthritis of the subtalar and talonavicular joints developed during the followup period in 17% and 11%, respectively. Progression of preexisting arthritis occurred in 13 of 43 patients (30%) at the subtalar joint and five of 26 patients (19%) at the talonavicular joint. None of these patients had fusion of an adjacent joint. The average American Orthopaedic Foot and Ankle Society score increased from 36 preoperatively to 85 at followup. Ankle arthrodesis with screws provides high rates of union, reliable pain relief, and favorable functional medium-term results. LEVEL OF EVIDENCE: Level IV, therapeutic study. See Guidelines for Authors for a complete description of levels of evidence.

Accuracy of corrective osteotomies in fibular malunion: a cadaver model.

BACKGROUND: While incorrect length of a fibular fracture reduction can be measured by plain radiographs, accurate imaging of rotational deformities requires computed tomography (CT). Operative correction of fibular malrotation has not been accurately measured. The aim of this study was to evaluate the accuracy of operative correction of fibular malrotation. MATERIALS AND METHODS: Six pairs of formalin-fixed, lower leg cadaver specimens had shortening with additional internal or external rotation induced by segmental fibular resection and plate fixation. The deformity was measured by CT. Two experienced surgeons performed standardized corrective operations on six specimens each. The postoperative results were measured by CT. RESULTS: The mean overall accuracy for correction of malrotation was 1.58 degrees (SD = 0.8 degrees). There were no significant differences between the two surgeons performing the corrections. CONCLUSION: The accuracy of operative correction of malrotation in this cadaver model is in accordance with the requirements reported in clinical studies. CLINICAL RELEVANCE: Considering the error margin for CT analysis, correction within 5 to 10 degrees seems practical.

Fifth metatarsal avulsion fracture: a rational basis for postoperative treatment.

BACKGROUND: Lacking rational basis for the postoperative treatment of fifth metatarsal avulsion fractures. METHODS: Biomechanical test of stability of tension banding and screw fixation of fifth metatarsal avulsion fractures in cadaver specimen, sonographic measuring of the maximum cross-section of the peroneus brevis muscle, electromyographic examinations of the activity of the peroneus brevis muscle at different loads and means of immobilization. RESULTS: The forces acting on the base of the fifth metatarsal bone during voluntary activation of the peroneus brevis muscle or activation in the gait cycle are of the same magnitude as the failure forces of internal fixation. Immobilization of the talocrural joint achieves no reduction in muscle activation. Partial weight bearing reduces muscle activation. CONCLUSIONS: The postoperative treatment after osteosynthesis of fifth metatarsal avulsion fractures should be partial weight bearing. For safety reasons we add an elastic ankle orthesis to prevent supination. A below-knee cast is not necessary.

In vivo effects of modification of hydroxyapatite/collagen composites with and without chondroitin sulphate on bone remodeling in the sheep tibia.

The addition of chondroitin sulphate (CS) to bone cements with calcium phosphate has lead to an enhancement of bone remodeling and an increase in new bone formation in small animals. The goal of this study was to verify the effect of CS in bone cements in a large animal model simulating a clinically relevant situation of a segmental cortical defect of a critical size on bone-implant interaction and bone remodeling. The influence of adding CS to hydroxyapatite/collagen (HA/Col) composites on host response was assessed in a standard sheep tibia model. A midshaft defect of 3 cm was created in the tibiae of 14 adult female sheep. The defect was filled with a HA/Col cement cylinder in seven animals and with a CS-modified hydroxyapatite/collagen (HA/Col/CS) cement cylinder in seven animals. In all cases the tibia was stabilized with an interlocked universal tibial nail. The animals in each group were analyzed with X-rays, CT scans, histology, immunohistochemistry, and enzymehistochemistry, as well as histomorphometric measurements. The X-ray investigation showed a significantly earlier callus reaction around the HA/Col/CS implants compared to HA/Col alone. The amount of newly formed bone at the end point of the experiment was significantly larger around HA/Col/CS cylinders both in the CT scan and in the histomorphometric analysis. There were still TRAP-positive osteoclasts around the HA/Col implants after 3 months. The number of osteopontin-positive osteoblasts and the direct bone contact were significantly higher around HA/Col/CS implants. We conclude that addition of CS enhances bone remodeling and new bone formation around HA/Col composites.

Transsection of the rectus abdominis muscle in the treatment of acetabular fractures: operative technique and outcome in 21 patients.

BACKGROUND: A standard ilioinguinal approach is often insufficient for reduction and stabilization of the medial acetabular wall and the dorsal column in acetabular fractures. To avoid extended approaches, we have used a medial extension of the approach by transverse splitting of the rectus abdominis muscle. We have thus been able to reduce and stabilize transverse and oblique fractures of the dorsal column and the medial acetabular wall and to fix plates in a mechanically better position below the pelvic brim. To evaluate the procedure, especially the risk of abdominal hernia, we started a prospective study. PATIENTS AND METHODS: Over 2 years, we treated 21 consecutive patients using a transverse splitting of the rectus abdominis muscle-either as an extension of the standard ilioinguinal approach or in combination with parts of this approach or a Kocher-Langenbeck approach. The patients were evaluated clinically and radiographically after 1 year. RESULTS: The clinical and radiographic results were excellent or good in 18 patients. Complications occurred in 5 patients. No hernias were observed. CONCLUSIONS: Our small study indicates that the procedure described is a useful and safe complement to the intrapelvic approaches. The procedure does not provide better reduction than extended approaches, but may help to avoid them in some cases.

Effect of chondroitin sulphate on material properties and bone remodelling around hydroxyapatite/collagen composites.

Chondroitin sulphate (CS) has an anti-inflammatory effect and increases the regeneration ability of injured bone. The goal of this study was to characterize the material properties and osteoconductive potency of calcium phosphate bone cements modified with CS. The early interface reaction of cancellous bone to a nanokristalline hydroxyapatite cement containing type I collagen (HA/Coll) without and with CS (HA/Coll/CS) in a rat tibia model was evaluated. Cylindrical implants were inserted press-fit into defect of the tibial head. Six specimens per group were analyzed at 2, 4, 7, 14, and 28 days. HA/Coll/CS composite cylinders showed a 15% increase in compressive strength and by investigations with powder X-ray diffraction more nontransformed cement precursor was found. The microstructures of both types of implants were similar. A significantly higher average number of TRAP positive osteoclasts and ED1 positive mononuclear cells were observed in the interface around HA/Coll/CS implants on day 4 and 7 (p < 0.05). At 28 days the direct bone contact and the percentage of newly formed bone were significantly higher around HA/Coll/CS implants (p < 0.05). The addition of CS appears to enhance bone remodelling and new bone formation around HA/Coll composites in the early stages of bone healing. Possible mechanisms are discussed.

Anatomical reconstruction of malunited talus fractures: a prospective study of 10 patients followed for 4 years.

BACKGROUND: Malunions or nonunions after displaced talar fractures cause significant disability. Salvage procedures such as corrective arthrodesis do not restore normal foot function. METHODS: Between 1994 and 2002, we treated 10 patients (aged 15-50 years) who had painful malunions with secondary anatomical reconstruction, at a mean of 1 year after sustaining displaced fractures of the talar body or neck. 5 patients were classified as type I (malunion and/or residual joint displacement), 2 as type II (nonunion with displacement) and 3 as type III (malunion with partial avascular necrosis, AVN). Correction was by an osteotomy through the malunited fracture or removal of the pseudarthrosis. Internal fixation was achieved with screws and additional bone grafting if necessary. RESULTS: No wound healing problems or infections were seen. Solid union was obtained without redislocation in all cases, with no signs of development or progression of AVN. At a mean of 4 (1-8) years after reconstruction, all patients were satisfied with the result--except one patient who required ankle fusion 8 years after reconstruction. The mean AOFAS Ankle Hindfoot Score increased from 38 to 86 (p < 0.001). INTERPRETATION: Secondary anatomical reconstruction with joint preservation leads to considerable functional improvement in painful talar malunions. Partial AVN does not preclude good to excellent functional results. The quality of the bone stock and joint cartilage (rather than the time from injury) appears to be important for the choice of treatment.

Metatarsal fractures.

Metatarsal fractures are relatively common and if malunited, a frequent source of pain and disability. Nondisplaced fractures and fractures of the second to fourth metatarsal with displacement in the horizontal plane can be treated conservatively with protected weight bearing in a cast shoe for 4-6 weeks. In most displaced fractures, closed reduction can be achieved but maintenance of the reduction needs internal fixation. Percutaneous pinning is suitable for most fractures of the lesser metatarsals. Fractures with joint involvement and multiple fragments frequently require open reduction and plate fixation. Transverse fractures at the metaphyseal-diaphyseal junction of the fifth metatarsal ("Jones fractures") require an individualized approach tailored to the level of activity and time to union. Avulsion fractures of the fifth metatarsal bone are treated by open reduction and tension-band wiring or screw fixation if displaced more than 2 mm or with more that 30% of the joint involved. The metatarsals are the most common site of stress fractures, most of which are treated nonoperatively. Symptomatic posttraumatic deformities need adequate correction, in most cases by osteotomy across the former fracture site.