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Biomedical subjects

M P Hahn

Publications and source records attributed to M P Hahn.

At least 19 recordsLinked to original sources
PubMed2004

[Pilon tibiale fractures].

In the AO classification, the distal tibia is 43 and A type injuries are extra-articular, B type partial articular and C type involve the whole of the articular surface with complete separation of the joint from the diaphysis. The term pilon fracture should be confined to B(3) and C type fractures. The injury mechanism of pilon fractures will vary from a simple fall to a high energy road traffic accident, leading to increasing fracture comminution and greater soft tissue injury with more open fractures. Plain radiographs and CT-scans are diagnostic prerequisites. A spanning external fixator, with or without fixing the fibula, is the initial method of choice. The goal is to span the zone of injury with the fixator, to align the limb, to reduce the articular surface through very limited approaches, and to minimize complications related to treatment to maintain length and provisionally align the fracture. When soft tissue swelling has subsided definitive stabilization is performed. Bone grafting of defects is rarely necessary.

Ankle Injuries↗
PubMed2003

[Primary hemiarthroplasty after complex fracture of the humeral head--functional late results].

UNLABELLED: Treatment of complex fractures of the humeral head remains an obviously unsolved problem. Under consideration of the problems of head preserving methods, the development of the last years tended towards the hemiprosthetic replacement. As the discussion about the methods and implants continues to be controversial, long-term results of Neer-II-replacement of humeral head in own trauma cases are presented here. PATIENTS AND METHODS: 46 patients were investigated, in whom a cemented Neer II hemiprosthesis was implanted between 1983 and 1996 due to complex fracture patterns. Median age was 60.2 years, 74 % of patients were female. 59 % had a luxation fracture type Neer VI, 22 % presented a concomitant nerval lesion. Follow up was performed 5 years on average after the operation. 38 patients were investigated clinically according the score of Constant and Murley, 36 had a x- ray control. Additionally an individual questionnaire was completed by 46 patients. RESULTS: Average Constant-score was 66.2 points, whereas in 76.3 % a satisfactory or better result was achieved. In 23.9 % the outcome was poor. In one patient (2.2 %) explantation of the hemiprosthesis and shoulder fusion due to pain was necessary. Conditions for a good result were a patient aged 50 years and younger (75.9 pts. versus 64.2 pts.), an early hemiprosthetic replacement within 4 weeks after the trauma (71.7 pts. versus 55.3 pts.) and a patient without an earlier operation and nerval lesion (76.8 pts. versus 53.9 pts.). No correlation was found between the date of the follow-up and the interval of time since the operation. CONCLUSION: After complex fractures of the humeral head satisfactory long-term results can be obtained by the cemented Neer II hemiprosthesis. Thus, implants of the newer generation can not yet whitness their superiority under consideration of functional aspects. Refixation and reintegration of both the tubercula after trauma still seems to be an unsolved problem and requires further development.

Adult↗
PubMed2002

[Differential therapy of radial head fracture: a critical analysis based on outcome of 53 patients].

We investigated 53 patients with 57 radial head fractures (4 patients with bilateral fractures) treated between 1993 and 1998. We focused on patients with radial head fractures asking about (1) the relation between fracture type and therapy and (2) the correlation between chosen treatment and result. We saw the following fractures: Mason I: 3 cases, Mason II: 26 cases, Mason III: 11 cases, and Mason IV: 15 cases. Good results were achieved by 30 patients with 31 fractures, fair results by 8 patients with 9 fractures, and poor results by 13 patients with 14 fractures. Patients with a Mason I fracture achieved good results with functional therapy. Of the 26 Mason II fractures, 14 were treated with screws, 14% of whom had poor results subjectively. Six patients were treated with a K wire, titanium nail, or prevot nail, none of whom had poor results. Of 11 patients with a Mason III fracture, 10 were treated by resection of the radial head, and in 1 patient we implanted a prosthesis due to an intraoperatively detected elbow instability after resection and achieved good postoperative results. Only one patient (9%) had poor long-term results subjectively. Of 15 patients with a Mason IV fracture, 11 were treated by resection of the radial head: 5 patients (33%) had poor long-term results, only 3 of whom (20%) subjectively considered the results poor.

Adolescent↗
PubMed2000

Fixation of proximal tibia fractures by a retrograde nail: a biomechanical investigation.

Surgical treatment of proximal tibial fractures requires open reduction and internal fixation. The operative exposure causes additional soft-tissue injury and reduces the blood supply to the bone. A cephalograde tibial nail should offer comparable mechanical stability without these disadvantages. We compared the stability of both osteosyntheses in a fracture model with 12 fresh-frozen cadaver bones. While both implants exhibited comparable stiffness under sagittal loading, the plate had a higher rotational and varus stiffness. Despite this higher stiffness, rotational displacements at the fracture gap were nearly twice as large for this implant during loading. We conclude that the retrograde nail provides similar mechanical stability to plate fixation for proximal tibial fractures, while the closed reduction and soft-tissue preservation of this new technique are definite advantages.

Biomechanical Phenomena↗
PubMed1999

[Results of posttraumatic elbow arthrolyses: a prospective study].

INTRODUCTION: Posttraumatic stiffened joints are mostly well restored by means of operation, however, the range of motion remains restricted by secondary soft tissue shrinking and scarring. Conservative treatment yields only limited success rates. Open arthrolysis is a useful tool in regaining function; in postoperative treatment, immediate passive mobilization and prevention of heterotopic ossification are most important. METHODS: Sixty-nine patients were arthrolyzed on average 25.3 months post trauma, with an average of 1.5 previous operations (range 0-8) and a follow-up period of 14.7 months. RESULTS: By means of the open arthrolysis, an increase in range of motion for flexion and extension of 62.3 degrees (preoperative 38.4 degrees, postoperative 87.9 degrees, at follow-up 100.7 degrees ) and 29.3 degrees for pro- and supination was achieved on average. The highly important range of motion between 0-30 degrees and 110 degrees was accomplished in 78.2 % of the patients. We analyzed the postoperative management including irradiation, pharmacological ossification prophylaxis with indomethacin and immediate passive motion. Whenever the time to arthrolysis exceeded 9 months, clearly worse results were obtained, thus we measured a difference in the correlated increase of motion from 54.3 % - 34.6 %. Comparisons of our results with German (after Blauth and Hipp) and French (after Cauchoix and Deburge) standard follow-up forms are made, and the rehabilitation program is underlined and explained. Another task of this study was to discuss the complication rate.

Adolescent↗
PubMed1999

[Pediatric forearm fractures: indications, technique, and limits of conservative management].

Although several "minimal invasive" techniques for the operative management of pediatric forearm fractures have been developed recently, conservative treatment still remains the option with the lowest risk for small patients. We present the results of our clinical and radiological follow-up after an average of 52.4 months (4-112) in 102 pediatric patients. All fractures were treated conservatively. There were 68 fractures (66.7 %) of the distal third of the forearm, 30 fractures (29.4 %) of the midshaft area, and four fractures (3.9 %) in the proximal third of the shaft. Greenstick fractures were seen in 58 cases (56.8 %), complete fractures with displacement of both corticalices in 26 patients (25.5 %), and folding fractures in 18 cases (17.7 %). With the exception of one fracture with the necessity of remanipulation after redisplacement in the cast, all fractures healed uneventfully without any further intervention. Functional results were excellent with a free range of motion of the wrist and elbow and without any signs of muscular atrophy in 96 children (94.1 %) at the time of follow-up. Six patients, however, showed a significant loss of forearm rotation of an average of 25 degrees (15 degrees -50 degrees ). In four of these six patients, the fracture had been situated in the proximal and midshaft area. Thus, two out of four fractures of the proximal forearm (50.0 %) showed a poor functional outcome. On the basis of our data we recommend conservative management for (closed) pediatric fractures of the distal and midshaft area. Operative treatment is indicated in forearm fractures close to the elbow.

Adolescent↗
PubMed1999

Surgical excision of heterotopic bone after hip surgery followed by oral indomethacin application: is there a clinical benefit for the patient?

The clinical effect of surgical excision of heterotopic bone after hip surgery in combination with an oral indomethacin application was analysed in 21 patients in a retrospective study. Indomethacin (3 x 50 mg) was administered after the first postoperative day for a period of 6 weeks. To avoid gastrointestinal side-effects, a mucoprotectivum (sucralfat, 3 x 1 g) was also applied. One year after surgery, 19 patients (90.4%) had excellent relief of pain, the average improvement of flexion was 40 degrees, of abduction 13 degrees, of internal rotation 8 degrees and of external rotation 14 degrees. Only one patient (4.8%) suffered a recurrence of heterotopic bone formation, and in one patient (4.8%) we observed gastrointestinal side-effects. Thus, we recommend surgical excision of heterotopic bone followed by oral indomethacin therapy as a convenient and reliable strategy to prevent new heterotopic bone formation after hip surgery.

Adolescent↗
PubMed1999

Arthrodesis of the infected ankle and subtalar joint: technique, indications, and results of 45 consecutive cases.

OBJECTIVE: To analyze the results of 45 patients after ankle arthrodesis in the presence of joint infection. METHODS: Arthrodesis was performed with two compression screws and an anterior plate in 29 patients and with two compression screws only in 16 patients. In all patients, additional stabilization with external fixation was used. In 29 patients, isolated fusion of the ankle joint was performed; in 13 patients, the ankle and subtalar joints were fused, and in 3 patients, isolated arthrodesis of the subtalar joint was performed. RESULTS: In 39 of 45 patients (86.6%), solid fusion was obtained. Nonunions occurred in 6 patients (13.4%). A below-knee amputation was necessary for one patient. Full weight-bearing was achieved after 21.6 weeks on average. Thirty-two patients returned to work after 35.5 weeks on average. Five of the six patients with failed ankle fusion needed special shoes; in one patient, a below-knee amputation was performed. A total of 33.3% of failed ankle fusions were associated with systemic disorders such as diabetes mellitus, and other concomitant diseases compromising local arterial blood supply and proprioception. CONCLUSION: Our results prove that limb salvage is possible even in complex ankle and subtalar pathology by thorough fusion by using a number of different techniques.

Adult↗
PubMed1998

[Ankle para-articular tibial fracture. Is osteosynthesis with the unreamed intramedullary nail adequate?].

In a prospective study, 53 fractures of the distal fifth of the tibia were stabilized by unreamed nailing. Additional involvement of the ankle joint occurred in 18 patients. 50 patients returned for follow-up. In 30 patients tibia and fibula were fractured at the same (distal) level; in 20 patients the fracture of the fibula was located more proximally. In 12 patients the fractures extended into the tibial pilon. Severe soft tissue damage was seen in 24 fractures (18 open, 6 closed). Ninety percent of all fractures healed uneventfully without further surgical intervention after unreamed nailing. In two patients the unreamed nail had to be exchanged for a reamed tibial nail. Bone grafting and secondary dynamization of the nail by removal of a proximal interlocking bolt were performed in one case each. Thirty-one fractures healed in anatomical position. Valgus or varsus angulation of less than 5 degrees occurred in 18 patients. One fracture healed with rotatory angulation of 15 degrees. The highest rate of complications (22%) was seen in patients with distal fractures of the fibula without additional plating (of the fibula). There was no deep infection. Tibial fractures close to the ankle joint can be managed by unreamed nailing. Distal fractures of the fibula should be stabilized by additional plating. Because of the unreamed technique of implantation this procedure can also be used in grade II or III open fractures.

Adult↗
PubMed1998

[Prostheses of the head of the radius. What outcome can be expected?].

We report our results after primary implantation of 30 radial head prostheses in a retrospective study from 1978 to 1996. If there was intraoperatively a remaining instability of the elbow after resection of the radial head, we implanted a prosthesis. The average age of our patients was 40.7 years. The results were evaluated concerning the recommendations of Radin and Riseborough. In 22 patients (73%) we found good to satisfactory results, in 8 patients (27%), there was a free range of motion. Heterotopic ossifications with a remarkable decrease in the range of motion were discovered in 3 patients (10%). The implant had to be removed in three (10%) patients (2 incorrect implantations, one broken prosthesis). To conclude, the primary implantation of a radial head prosthesis after a strict indication improves the clinical benefit for the patient. A correct surgical technique avoids unnecessary complications.

Adult↗
PubMed1998

Major injury induces increased production of interleukin-10 in human granulocyte fractions.

Patients with severe trauma or polytrauma frequently acquire alterations in immune functions which are correlated to dysbalanced cytokine synthesis. In these settings the role of polymorphonuclear neutrophil granulocytes (PMN) as cytokine-producing cells is less well characterized. The immunosuppressive role of interleukin (IL)-10 is well known, and increased systemic IL-10 levels are related to the severity of injury and to posttraumatic complications. We determined concentrations of IL-10 in culture supernatants of 30 individual PMN fractions isolated from 18 severely traumatized patients (15 polytraumata, Injury Severity Score: 18-41, 3 severely burned patients) admitted to intensive care units. IL-10 was analyzed by ELISA (R&D Systems, Wiesbaden, Germany). PMN were isolated from EDTA-anticoagulated peripheral blood employing a one-step procedure based on a discontinuous double Ficoll gradient. The cells [1 x 10(6)/ml RPMI 1640 supplemented with 10% fetal calf serum and 25 mM N-(2-hydroxyethyl)-piperazine-N'-(2-ethanesulfonic acid] were stimulated with 0.05% heat-killed Staphylococcus aureus (Pansorbin, Calbiochem-Novabiochem, Bad Soden, Germany) for 24 h using cell culture conditions. Our results show that PMN fractions of traumatized patients produce significantly (P<0.008) higher amounts of IL-10 (354+/-95 pg/ml, n = 30) than normal healthy donor cells (125+/-95 pg/ml, n = 7). IL-10 release from PMN fractions exceeded the release from isolated patients' peripheral blood mononuclear cells induced by similar stimulation or by stimulation with toxic shock syndrome toxin-1 (10 ng) and concanavalin A (2 microg). Our results provide evidence that PMN fractions play an active role in the development of posttraumatic immunosuppression by autocrine or paracrine mechanisms, for example, by suppressing one's own antimicrobial activities or determining the development of T-cell responses via their ability to release IL-10.

Adolescent↗
PubMed1998

[Liberation of interleukin 12 (IL12) after trauma and polytrauma].

We determined concentrations of IL-12 (p70), IL-12 (p40) and concomitantly of IL-10 in plasma and partly in culture supernatants stimulated peripheral blood mononuclear cells (PBMC) of 30 traumatized patients (ISS: 17-57; APACHE II: 7-45; during their course on the intensive care unit. Our results showed that individually systemic IL-12 could be extremely increased post trauma (p70 > 1000 pg/ml and p40 > 2500 pg/ml). Patients who succumbed to sepsis/multi organ failure, partly exhibited subnormal systemic IL-12-values. The capacity to synthesize IL-12-p40 from SAC-stimulated PBMC in vitro was individually increased in non-septic patients and correlated to respective plasma values.

APACHE↗
PubMed1998

[Elastic intramedullary nailing--a concept for treatment of unstable forearm fracture in childhood].

The standard treatment in forearm fractures of children is usually conservative. Unstable fractures of the proximal parts of the forearm often show poor results after nonoperative management, requiring surgical intervention. We report on 30 children from 4 to 14 years of age who were treated by elastic intramedullary nailing. Sixteen patients were treated by intramedullary pinning immediately after the accident; 14 required intramedullary nailing after failure of the conservative treatment and fracture redislocations. At the time of follow-up 6 months later, functional results were "excellent" in 24 children, "good" in 5 and "fair" in one child. There were no serious complications apart from the occurrence of one delayed union. According to these results intramedullary nailing can be recommended for the treatment of unstable fractures of the proximal and middle parts of the forearm in children.

Adolescent↗
PubMed1997

[Traumatic axial dislocation injury of the carpus and metacarpus with triquetrum fracture. Rare entity or typical injury].

Although there are only 39 reports of compression injuries with axial dislocation of the carpus and metacarpus, there are similar patterns of injury. In all cases the dislocation is located either between the first and second or the third and fourth metacarpals and the corresponding carpal bones so that weak points of the carpal arch can be assumed in these regions. Clinical and radiological findings in a 22-year-old patient with dislocation of the third and fourth metacarpals and a fracture of the os triquetrum of the right hand after compression injury of both forearms with severe soft tissue injuries are described. Wound débridement and subsequent skin grafting were performed. The osseous lesions were reduced and held by two Kirschner wires and an external fixator. Results at follow-up were satisfactory.

Accidents, Occupational↗