Explantation and analysis of the first retrieved human acetabular cup made of polycarbonate urethane: a case report.

This report describes the first human retrieval of a polycarbonate-urethane (PCU) acetabular cup implanted for 10.5 months that was revised for pain of unknown origin. By using a micro-CT analysis, the articulating surface was determined to have a wear rate of less than 1.4 mm3 per year. An analysis of the synovial fluid retrieved at the time of revision found an average particle size of 1 mum diameter. Overall, the surgical findings and analysis were consistent with the results observed in laboratory and animal studies. The histology and synovial fluid analysis found sparse evidence of particulate debris and no synovitis, indicating the potential of this articulating material for use as a bearing surface.

Joint position awareness and sports activity after capsulolabral reconstruction in the overhead athlete.

A total of 24 overhead athletes with posttraumatic, chronic anterior shoulder instability underwent surgery. Twenty-two patients were examined after an average follow-up of 2.8 +/- 0.7 years. On average, a Constant-Score and Constant-Murley-Score of 93.7 +/- 5.3 points and an ASES-Score of 95.0 +/- 5.1 points were achieved. The redislocation rate was 9 %. The study demonstrated, that despite the good clinical results, only 12 out of 22 (55 %) of patients were able to return to their previous sports activity level. This relevant problem is in agreement with other similar studies [ ], so it was further addressed by determination of joint position awareness (JPA) and electromyographic muscle activity. Postoperatively, a persisting deficit of JPA, as well as an altered EMG pattern, was found with a significant reduction in activity of the deltoideus muscle on the operated side. The analysis of the data of each patient showed that there was a significant relation between the restitution of JPA and ability to return to the previous sports activity level. In contrast, the relation between EMG pattern and full recovery to completely unrestricted shoulder function was not significant. The anterior capsulolabral reconstruction enables a reliable restoration of shoulder stability and a low rate of complications. The problem that a relatively high percentage of overhead athletes can not return to their previous performance level is based on an impaired joint position awareness.

[Sensorimotor potential of the intact and injured anterior and posterior cruciate ligaments--a neurophysiological study in an animal model]. / Sensomotorisches Potenzial vom intakten und traumatisierten vorderen und hinteren Kreuzband -- eine tierexperimentelle, neurophysiologische Studie.

AIM: This neurophysiological study is intended to investigate the sensomotor potential of the anterior cruciate ligament (ACL) and the posterior cruciate ligament (PCL) which may provide joint stabilization via a ligamentomuscular reflex arch. In addition, the role of ligamentous injury on the sensomotor potential has been investigated. METHOD: The sensomotor potential was investigated using 24 knee joints in a sheep model under in-vivo conditions. The cruciate ligaments were mechanically loaded and the muscular activities of the hamstrings and the quadriceps were recorded simultaneously via electromyography. Injury to the ligaments was simulated by defined mechanical elongation of the ACL and PCL to failure. RESULTS: The results confirm the hypothesis of the existence of a ligamentomuscular reflex loop between ligamentary mechanoreceptors and the joint-stabilizing muscles. Mechanical loading of the ACL triggered mainly the activity of the hamstrings, whereas loading of the PCL led to the activation of the quadriceps. The rate of elongation which caused disturbances to the sensomotor potential was significantly smaller as compared to the elongation to failure. CONCLUSION: The cruciate ligaments provide dynamic joint stabilization via a ligamentomuscular reflex arch. It was demonstrated that the sensomotor potential of both structures is significantly more susceptible to ligament injury than the biomechanical potential.

[Acute colonic pseudoobstruction following fixation of a pertrochanteric fracture]. / Akute intestinale Kolonpseudoobstruktion 2 Tage nach Versorgung einer pertrochantären Femurfraktur.

Acute colonic pseudoobstruction, following traumatic injuries, is a rare diagnosis. Nevertheless it is life threatening, if it is not recognized and treated promptly. We report one case of this so-called Ogilvie's syndrome, which followed fixation of a trochanteric fracture by intramedullary nailing within 2 days. Due to massive acute colonic distension, the patient suffered from respiratory failure. We excluded other intestinal diseases by CT scanning. After conservative colonic decompression, he recovered after 2 days in the intensive care unit. We describe a variable treatment depending on the severity of the colonic atony. Knowledge of Ogilvie's syndrome, or acute colonic pseudoobstruction, is a must for trauma surgeons, since it can occur within a few hours and can lead to dramatic situations.

[Sensorimotor deficit after capsulolabral reconstruction in chronic instability of the shoulder. A clinical experimental study]. / Sensomotorik nach Kapsellabrumrekonstruktion bei chronischer Schulterinstabilität. Eine klinisch-experimentelle Studie.

The anterior capsulolabral reconstruction technique described by Jobe is a modified Bankart repair. The capsular shift is performed in a horizontal direction via a subscapularis split approach avoiding any incision of the muscle. Of 43 patients with posttraumatic anterior shoulder instability treated by anterior capsulolabral reconstruction, 35 were examined after 3.7+/-1.4 years, and of these, 29 (82.9%) had no pain; the external rotation deficit was 4.1+/-2.9 degrees . The average Constant-Murley score was 92.4+/-7.1 and the average ASES score was 93.3+/-8.4. The reluxation rate was 7.7%. This technique was shown to provide good clinical results, but only 69% of the patients were able to return to their prior sporting activity level. This particular problem was addressed by investigating the joint proprioception and the activity of the periarticular muscles. The results confirmed a persistent deficit of proprioception as well as a pathologic EMG pattern after anterior capsulolabral reconstruction, which may explain the problem of incomplete restoration of the function of the shoulder joint.

[Capacity for sport and the sensorimotor system after stabilization of the shoulder in overhead athletes]. / Sportfähigkeit und Sensomotorik nach Schulterstabilisierung beim Uberkopfathleten.

The anterior capsulolaboral reconstruction according to Jobe is a modification of the Bankart operation, performing the capsular shift via a subscapularis-split approach avoiding any incision into the musculature. A total of 24 overhead athletes with posttraumatic, chronic anterior shoulder instability underwent surgery. Twenty-two patients were examined after an average follow-up of 2.8 +/- 0.7 years. On average, a Constant-Murley-Score of 93.7 +/- 5.3 points and an ASES-Score of 95.0 +/- 5.1 points were achieved. The relaxation rate was 9 %. The study demonstrated, that despite the good clinical results, only 12 out of 22 (55 %) of patients were able to return to their previous sports activity level. This relevant problem is in agreement with other similar studies so that it was further addressed by determination of proprioception and electromyographic muscle activity. Postoperatively, a persisting proprioceptive deficit as well as an altered EMG pattern was found with a significant reduction in activity of the deltoideus muscle on the operated side. The analysis of the data of each patient showed that there was a significant relation between the restitution of proprioception and ability to return to the previous sports activity level. In contrast, the relation between EMG pattern and full recovery to completely unrestricted shoulder function was not significant.

[PMMA pulmonary embolism and post interventional associated fractures after percutaneous vertebroplasty]. / PMMA Lungenembolisation und postinterventionelle Anschlussfrakturen nach perkutaner Vertebroplastie.

A 78-year old woman with osteoporotic collapse of the Th12 and L4 vertebrae was treated by percutaneous vertebroplasty (pVp) with PMMA (polymethylmethacrylate). Postoperatively, the Th11 and L1 vertebrae collapsed so that a second vertebroplasty was performed. Postoperatively, the patient developed a severe pulmonary embolism which was treated conservatively. In this report, the complications of pulmonary embolism, perivertebral leakage of PMMA and of additional vertebral collapses after pVp are discussed.

Failure of operative treatment in a child with osteoporosis-pseudoglioma syndrome.

A 6-year-old girl with osteoporosis-pseudoglioma syndrome had operative treatment of a distal femur fracture that failed. Osteoporosis-pseudoglioma syndrome is an autosomal recessive syndrome combining severe premature osteoporosis with a bilateral eye disorder leading to early onset of blindness. Beginning in early childhood, the patient sustained multiple fractures of the left distal femur that were treated nonoperatively. At the age of 5 years the patient had a fracture of the left distal femur with an 80 degrees angulation in the sagittal plane. The patient was treated with internal stabilization because of gross bowing of the femur at the fracture site. Intraoperatively, anatomic reduction was achieved by insertion of a flexible nail but not without some intraoperative problems. Because of the severe osteoporosis, iatrogenic penetration and fracture of the femoral cortex by the nail occurred intraoperatively in the subtrochanteric region. In addition, a hip spica cast was applied. The nail was removed 1 week later. After 6 weeks wearing the hip spica cast, the patient's fracture healed with some shortening but with correction of the angulation in the sagittal plane. Internal stabilization seems to be potentially troublesome in patients with severe forms of this syndrome and severe bony deformities.

Plantar impact causing midfoot fractures result in higher forces in Chopart's joint than in the ankle joint.

PURPOSE: Force effect (impact, extent of foot compartment deformation) and result (fracture pattern) for midfoot fractures in car occupants is known. An analysis of the processes in the foot was intended to improve car safety. MATERIALS AND METHODS: Eleven fresh, unfrozen, unpreserved intact human cadavers (age: 36.8 (16-61) years, gender: male, race: Caucasian) were studied 24-72 h after death. In 3 cadavers (5 feet) the experimental design was established: entire cadaver fixed on a special tray in supine position, pendulum with bar impactor hitting the foot plantar to Lisfranc's joint. A custom-made pressure sensor was inserted in the ankle (A), talonavicular (TN) and calcaneocuboid (CC) joints (resolution: 1 cm2, sampling rate: 500/s). RESULTS: Sixteen feet were measured: midfoot fractures were induced in 11 feet. The maximum pressure amounted to 1.22-2.55 MPa (2.04+/-0.412) at 0.005 0.195 s (0.067+/-0.059) after impact. The maximum pressure occurred in 8 (50%) cases in the ankle, in 7 (44%) of the TN and 1 (6%) of the CC joints. A comparison of the first 200 pressure samples after impact of all sensor fields resulted in higher forces in Chopart's joint than in the ankle (t-test: p < 0.001). These force differences were higher in cases with midfoot fractures (mixed model analysis of variance: p = 0.003). CONCLUSION: Due to considerable forces in Chopart's joint we recommend a modification of the actual crash test dummy lower extremity model with an additional load cell that detects forces in the longitudinal direction of the foot axis.

[Post-traumatic osteoid osteoma. Case report and review of the literature]. / Posttraumatisches Osteoidosteom. Fallbericht und Literaturübersicht.

Osteoid osteoma is a painful benign bone neoplasm that is rarely described after trauma but should be suspected. A case of osteoid osteoma 19 years after a tibial fracture is presented. The patient had pain in the tibia for 6 years before the osteoid osteoma was confirmed. He had been operated on twice for suspected osteomyelitis although the clinical symptoms suggested an osteoid osteoma. The radiographic appearance as well as a bone scan confirmed the diagnosis. Removal of the nidus resulted in immediate pain relief. A precise preoperative diagnosis of the lesion based on clinical findings, standard radiographs, high-resolution CT, and bone scan is mandatory. It is important to recognize this uncommon entity to avoid morbidity associated with a prolonged delay in diagnosis.

Fractures and fracture dislocations of the midfoot: occurrence, causes and long-term results.

Etiology and outcome of 155 patients with midfoot fractures between 1972 and 1997 were analyzed to create a basis for treatment optimization. Cause of injuries were traffic accidents (72.2%), falls (11.6%), blunt injuries (7.7%) and others (5.8%). Isolated midfoot fractures (I) were found in 55 (35.5%) cases, Lisfranc fracture dislocations (L) in 49 (31.2%), Chopart-Lisfranc fracture dislocations (CL) in 26 (16.8%) and Chopart fracture dislocations (C) in 25 (16%). One hundred and forty eight (95%) of the midfoot fractures were treated operatively; 30 with closed reduction, 115 with open reduction, 3 patients had a primary amputation. Seven (5%) patients were treated non-operatively. Ninety seven (63%) patients had follow-up at an average of 9 (1.3-25, median 8.5) years. The average scores of the entire follow-up group were as follows: AOFAS - sum of all four sections (AOFAS-ET): 296, AOFAS-Midfoot (AOFAS-M): 71, Hannover Scoring System (HSS): 65, and Hannover Questionnaire (Q): 63. Regarding age, gender, cause, time from injury to treatment and method of treatment no score differences were noted (t-test: p>0.05). L, C or I showed similar scores and CL significantly lower scores (AOFAS-ET, AOFAS-M, HSS, Q). The highest scores in all groups were achieved in those fractures treated with early open reduction and operative fixation. Midfoot fractures, particularly fracture dislocation injuries, effect the function of the entire foot in the long-term outcome. But even in these complex injuries, an early anatomic (open) reduction and stable (internal) fixation can minimize the percentage of long-term impairment.

Foot fractures in restrained front seat car occupants: a long-term study over twenty-three years.

OBJECTIVES: To analyze the mechanism of injury for foot and ankle fractures resulting from automobile accidents to create a basis for developing an improved design for protection. DESIGN: Retrospective. SETTING: Level I trauma center with accident research unit. PATIENTS: Automobile accident reports and medical records of individuals injured in the accidents. MAIN OUTCOME MEASUREMENTS: Technical indicators (collision type, impulse angle, deltav, and extent of vehicle deformation) and clinical data (injury location and severity [abbreviated injury scale and injury severity score] and long-term outcome). RESULTS: From 1973 to 1996, 15,559 car accidents were analyzed. Two hundred sixty-one front seat occupants sustained fractures of the foot and ankle (ankle, 41 percent; forefoot, 29 percent; midfoot, 20 percent; and hindfoot, 10 percent). Seventy-five percent of the fractures were classified abbreviated injury scale(foot) 2. The incidence, location, and abbreviated injury scale(foot) category of fractures were similar between driver (n = 210) and front seat passenger (n = 51). Fifty percent of the fractures occurred in head-on collisions and 34 percent occurred in accidents with multiple collisions. The deltav ranged in 82 percent of car crashes between fifteen and sixty kilometers per hour. The deltav and extent of foot compartment deformation correlated with the abbreviated injury scale. During our investigation, deltav increased; the injury severity score decreased; and the extent of deformation did not differ significantly. CONCLUSIONS: Although overall car passenger safety has improved, the relative incidence of foot and ankle fractures has increased. Comparing drivers and front seat passengers, the foot pedals, steering wheel, or the asymmetric design of the dashboard did not influence injury incidence, mechanism, or severity. Foot fractures are mainly caused by the foot compartment deformation in head-on collisions, and therefore improvements in foot compartments are essential for fracture prevention.

[Effect of needle acupuncture on pain perception and functional impairment of patients with coxarthrosis]. / Einfluss der Nadelakupunktur auf Schmerzwahrnehmung und Funktionseinschränkung bei Patienten mit Koxarthrose.

OBJECTIVES: The effectiveness of acupuncture treatment in patients with osteoarthritis of the hip was tested. DESIGN: This is a prospective, randomized, controlled patient and examiner blinded clinical trial. PATIENTS AND SETTING: The study was performed at a university department for physical medicine and rehabilitation. Sixty-seven patients were separated into two treatment groups. INTERVENTIONS: Group 1 (treatment) had traditional needle placement and manipulation, whereas in group 2 (control) needles were placed away from classic positions and not manipulated. In both groups needles were placed within the L2 to L5 dermatomes. Endpoints were pain (VAS), functional impairment (hip score), activity of daily living (ADL) and overall satisfaction before treatment, 2 weeks and 2 months post-intervention. RESULTS: For all endpoints there was a significant improvement in both groups 2 weeks and 2 months following treatment versus baseline, but no significant difference between the two treatment groups. CONCLUSIONS: We conclude from these results that needle placement in the area of the affected hip by itself improves symptoms of osteoarthritis. It appears to be less important to follow the rules of traditional acupuncture techniques.

[Healing of autologous cancellous bone transplants and hydroxylapatite ceramics in tibial segment defects. Value of ultrasonic follow up]. / Einheilung von autologen Spongiosatransplantaten und Hydroxylapatitkeramiken im Tibiasegmentdefekt. Wert der sonographischen Verlaufskontrolle.

The aim of this study was to develop and test a scoring system based on real-time ultrasonography (US), which is able to predict the healing of a bone defect filled with a bone graft substitute or cancellous bone graft. We implanted porous hydroxy-apatite (HA) ceramic blocks into a segmental defect in the tibia of 51 sheep; 14 sheep received autologous bone graft from the iliac crest. Follow-up times were 3, 6 and 12 months. With the exception of the 12-month animals, there was a minimum of 6 animals in each group. At the end of follow-up the tibiae were tested in torsion to failure. These results were correlated with radiographic and ultrasound scores measured on the same specimens. With the scoring system it was possible to describe the osseous integration of the HA ceramic or mineralisation of the cancellous bone graft. Sheep with ceramic implant that developed non-unions showed a significantly lower score than sheep with a sufficient implant integration. A significant correlation between these scores and the biomechanical results was found. We were able to define a cut-off within the scoring system which made the prediction of instability/non-union possible. In our model we were able to predict the osseous integration of HA ceramics and autologous cancellous bone grafts with the use of real-time ultrasound.

Resorbable calcium phosphate particles as a carrier material for bone marrow in an ovine segmental defect.

Resorbable calcium phosphate ceramics are only osteoconductive; therefore, their combination with osteogenic substances may lead to stimulation of bone healing. In the present study this combination, using autologous bone marrow, was investigated. In 31 sheep, a 3-cm tibial segmental defect was created and stabilized with an intramedullary nail. The animals were divided into four groups: empty defects (group 1, n = 7), and defects filled with 10-mL dense resorbable calcium phosphate particles (group 2, n = 8), with 10-mL particles soaked in bone marrow (group 3, n = 8), or with 10-mL autologous bone (group 4, n = 8). On evaluation after 12 weeks, significantly higher values were seen in group 3 than in group 2 for callus volume (p = .016), bone mineral density ratio (p = .03), bone mineral content ratio (p = .04), torsional strength (p = .005), and torsional stiffness (p = .01). For all end points, the outcome of group 3 was lower than that of group 4. In the histology, there was direct contact between newly formed bone and remnants of the particles. There were no signs of inflammatory reactions. Although a stimulatory effect of bone marrow was seen, the combination of resorbable calcium phosphate particles with bone marrow does not provide an alternative for autologous bone grafting.

Free flap to the arteria peronea magna for lower limb salvage.

A 36-year-old woman sustained an amputation of her right leg at the thigh level and a degloving injury of her left foot and ankle region in an accident during a suicide attempt. Primarily, her left foot was covered with a split skin graft, resulting in a soft-tissue defect at the medial malleolus and at the calcaneus bone. Reconstruction was planned with a free latissimus dorsi muscle flap. Preoperative examinations revealed an arteria peronea magna with a hyperplastic peroneal artery solely providing arterial blood supply to the foot. The arteria peronea magna divided into two branches proximal to the upper ankle joint, replacing the dorsal pedis artery and the medial plantar artery. Tibial posterior and tibial anterior arteries were hypoplastic-aplastic. Microvascular end-to-end anastomoses of the flap vessels to the medial branch ("medial plantar artery") of the arteria peronea magna and its concomitant vein at the medial malleolar bone level were successfully performed. The postoperative course was uneventful. Four weeks postoperatively, the patient started walking assisted by a prosthesis on her right thigh stump. This experience demonstrates that even in a case of arteria peronea magna, free flap surgery for lower limb salvage is a reliable and worthwhile method.

New segmental long bone defect model in sheep: quantitative analysis of healing with dual energy x-ray absorptiometry.

An appropriate animal model is required for the study of treatments that enhance bone healing. A new segmental long bone defect model was developed for this purpose, and dual energy x-ray absorptiometry was used to quantify healing of this bone defect. In 15 sheep, a 3-cm segmental defect was created in the left tibia and fixed with an interlocking intramedullary nail. In seven animals, the defect was left empty for the assessment of the spontaneous healing response. In eight animals serving as a positive control, autologous bone grafting was performed. After 12 weeks, healing was evaluated with radiographs, a torsional test to failure, and dual energy x-ray absorptiometry. The mechanical test results were used for the assessment of unions and nonunions. Radiographic determination of nonunion was not reliably accomplished in this model. By means of dual energy x-ray absorptiometry, bone mineral density and content were measured in the middle of the defect. Bone mineral density was 91+/-7% (mean +/- SEM) and 72+/-6% that of the contralateral intact tibia in, respectively, the autologous bone-grafting and empty defect groups (p = 0.04). For bone mineral content, the values were, respectively, 117+/-18 and 82+/-9% (p = 0.07). Torsional strength and stiffness were also higher, although not significantly, in the group with autologous bone grafting than in that with the empty defect. Bone mineral density and content were closely related to the torsional properties (r2 ranged from 0.76 to 0.85, p < or = 0.0001). Because interlocking intramedullary nailing is a very common fixation method in patients, the newly developed segmental defect model has clinical relevance. The interlocking intramedullary nail provided adequate stability without implant failure. This model may be useful for the study of treatments that affect bone healing, and dual energy x-ray absorptiometry may be somewhat helpful in the analysis of healing of this bone defect.

The influence of hydroxyapatite granules on the healing of a segmental defect filled with autologous bone marrow.

Hydroxyapatite(HA) ceramics are frequently used as a bone graft substitutes for the filling of bony defects. The addition of autologous bone marrow to HA ceramics does improve defect healing. There is conflicting evidence in the literature whether autologous bone marrow transplantation alone is as effective as the combination of HA ceramics and bone marrow combined. It was the purpose of this study to identify the role of additional HA ceramic granules on the healing of a sheep tibia segmental defect filled with autologous bone marrow. After permission of the local animal rights committee was obtained, a 3 cm segmental defect in the midshaft of 31 adult sheep was stabilized with an unreamed tibia nail. The animals were divided into 4 groups according to the mode of defect filling: HA plus autologous bone marrow (HA + MAR) (n = 8), autologous bone marrow (MAR) (n = 9), empty defect (DEF) (n = 6), cancellous bone graft (CAN) (n = 8). After three months follow up animals were sacrificed and analysed for the key parameters of union and maximum torque at failure. One nonunion was present in each of the HA + MAR, MAR, and CAN groups. Four of the six animals in the DEF group developed a nonunion. Maximum torque at failure was reported as percentage of the intact contralateral tibia: HA + MAR 39% +/- 24%, MAR 26% +/- 17%, DEF 22% +/- 13%, CAN 41% +/- 20%. The difference between the groups was statistically significant, but appeared to be relevant. We conclude from our data, that HA ceramics do improve healing of a segmental defect in the sheep tibia filled with autologous bone marrow. The results of this combination are comparable to cancellous autograft.