[Bilateral ankylosing paraarticular ossifications of the hip joint with involvement of the sciatic nerve]. / Oboustranné ankylozující paraartikulární osifikace kycelních kloubu s plegií n. ischiadicus.

In December 1997 a 48 year-old man was treated by resection of the bilateral paraarticular ankylosing ossifications that developed after 6 weeks of unconsciousness after necrotic pancreatitis. The ossifications on the posterior part of the hip joint involved a highly separated sciatic nerve. There was a bilateral osseous ankylosis of the hip joint and total denervation of sciatic nerve. In April 1999 the ossifications on the right side were removed. The splitted sciatic nerve was in two osseous channels. The head of the femur was vital and immediately following the operation, flexion of the hip joint was possible to 90 degrees. The same procedure was performed on the left hip joint in October 1999. In April 2000, a re-occurance of the paraarticular ossification on the ventral part of the right hip joint was removed from an ilioinquinal approach. In June 2002 the patient was able to stand and walk without crutches. ROM of the knee joints improved bilaterally to 120 degrees of flexion. The flexion of the right hip joint is 70 degrees and in the left hip is 80 degrees. 3 years after decompression of both sciatic nerves involved in heterotopic bone established significant reinervation. The motor function of the proximal femoral muscles and the function of the tibial nerve was renewed. Complete motor denervation syndrom persists in common peroneal nerve. Sensitive inervation was renewed as in n. tibialis as in common peroneal nerve except acral parts of the foot a toes. Concerning function of the sciatic nerves, the overall results can be assessed as partially succesfull because of partial denervation syndrome of sciatic nerves. In definite clinical improvement the recovery of the neurologic status is very important besides the mechanical improvement of range of motion of the hip joint.

[Initial experience with implantation of the cemented Beznoska/S.V.L. total knee joint endoprosthesis]. / První zkusenosti s implantací cementované totální endoprotézy kolenního kloubu typu Beznoska/S. V. L.

PURPOSE OF THE STUDY: The authors present the results of their first trial of a new, Beznoska/S. V. L. type, knee prosthesis in order to introduce it to a broad orthopedic public. MATERIAL: Clinical and radiological evaluation was carried out on 34 knee prostheses implanted in 31 patients between September 1997 and October 1999. The average patient age at the time of surgery was 71.3 years and the average interval between surgery and assessment was 22.4 months (range 6 to 31 months). All patients underwent implantation due to primary or secondary gonarthosis. A brief description of the implant and the instrumentation and used surgical technique is provided. METHODS: Clinical outcomes were evaluated according to the "Knee-Society Clinical Rating System" by John N. Insall. The system classifies both knee joint parameters and knee function. X-ray films were assessed on the basis of the "Knee-Society Total Knee Arthroplasty Roentgenographic Evaluation and Scoring System" by Frederic C. Ewald. In standardized X-ray projections, this allowed us to evaluate the implant position as well as radiolucent lines. RESULTS: On stability evaluation, we found anteroposterior instability up to 5 mm in 85% of the implants and mediolateral instability up to 9 degrees in 97% of them. A maximum flexion of 90 degrees to 120 degrees was achieved in 91% of the implants. The final outcome in terms of knee score was on average 80.3 points (range, 40 to 97 points), which was a very good result. Evaluation by function score showed that only 17% of the patients were not able to walk farther than 500 meters. Although 82% of them had to hold on a railing when going upstairs, all were able of stair ascent and descent; 13% had to use a walking stick permanently. The average function score was 68.4 points (range, 30 to 100), which was a good outcome. Radiograms in anteroposterior projection, assessed according to Ewald, showed the average femoral flexion angle (alpha) to be 95.2 degrees, the average tibial angle (beta) to be 89 degrees and the total valgus angle (omega) to be 3.2 degrees. In lateral projection, the femoral flexion angle (gamma) was on average 2.5 degrees and the average tibial angle (delta) was 86.7 degrees. An optimal position of the patella was achieved in 27 implants. Five radiolucent lines, up to 1 mm, were found in zone 1 of the femoral component and further lines were observed in zones 1, 2 and 4 of the tibial component. DISCUSSION: When assessing the results by the knee and function scores, it had to be taken into consideration that the average age of the patients was 71.3 years. At this age, walking without a stick, or stair ascent or descent without the use of a railing can hardly be expected. The average result of 68.4 points achieved can, therefore, be considered a very satisfactory outcome. The values shown by X-ray examination were close to the normal condition. The patients were also asked for their subjective opinion of the effect of arthroplasty; 97% of them regarded the effect as good or very good, only one patient reported no benefit. CONCLUSIONS: The results of the first trial of the use of a cemented prosthesis, type Beznoska/S. V. L., in total knee arthroplasty are presented, together with practical recommendations. Although the patient sample was small and the follow-up period short, the results are promising and suggest excellent prospects for this implant.

[Distal shortening osteotomy of the metatarsals using the Weil technique: surgical treatment of metatarsalgia and dislocation of the metatarsophalangeal joint]. / Weilova distální zkracovací osteotomie metatarzu: chirurgické lécení metatarzalgie a dislokace v metatarzofalangeálních kloubech.

PURPOSE: Weil technique of the distal shortening osteotomy of metatarsal is a relatively new method of the surgical treatment of metatarsalgia and dislocation of metatarsophalangeal (MTP) joints. A retrospective study evaluates the first experience in Weil osteotomy at the authors' department. MATERIAL: Between May 1999 and the end of 2000 twelve patients (14 feet) were operated on in which the Weil technique of the osteotomy was performed on 28 metatarsals. Indication for the surgery was chronic metatarsalgia with dislocation of the MTP joint, with excessive length of one or more lesser metatarsals, with insufficiency of the first ray after the surgery of hallux valgus and metatarsalgia after the resection of the head of II metatarsal. All patients were women, average age of 57 years (range, 50-68 years) at the time of operation. The average follow-up is 9 months (range, 6-24 months). Dislocated prior to operation were 9 MTP joints, in 2 cases a deformity of 2nd digit of the digitus supraductus type was operated on. METHODS: The patients evaluated subjectively the functional and cosmetic outcomes of the surgery. Clinical evaluation related to recurrence or transfer of difficulties to the head of the neighbouring metatarsal, range of motion of the MTP joint, function and grip of the digit. Radiograph was used for the evaluation of the metatarsal index, post-operative shortening of II metatarsal, reduction of dislocation in the MTP joint and healing of osteotomy. RESULTS: Satisfied with the functionla and cosmetic results of the operation were 83% patients (10 of 12). Recurrence of metatarsalgia was not found in any patient, transfermetatarsalgia in one patient. Reduction of the range of motion in the MTP joint (plantar flexion) by more than 50% was recorded in 43% operated on metatarsals and in all metatarsals after the reduction of the dislocation. Acceptable function and strength of the digit evaluated by the ability to press by the digit a sheet of paper against the floor was preserved in most of the operated on metatarsals--86% (24 of 28). Average shortening of II metatarsal was 5.6 mm. All dislocated MTP joints were reduced postoperatively. Dislocation recurred in 2 cases. Avascular necrosis of the head of II metatarsal after the reduction of the dislocation was encountered in one case. DISCUSSION: The small number of recurrences and transfermetatarsalgia proves that Weil osteotomy allowing a controlled shortening of metatarsal with a fixation is a reliable method in the solution of metatarsalgia. The operation directly on the joint allows reduction of the dislocation of the MTP joint. Shortening of metatarsal facilitates reduction and reduces axial pressure in the MTP joint. Recurrence of dislocation is reported between 15% and 22%. After a more difficult reduction and danger of redislocation some authors recommend a temporary transfixation of the MTP joint by K-wire. The disadvantage of the operation is a frequent temporary limitation of the range of motion in the MTP joint which is caused by the opening of the articular capsule and its subsequent contraction. No author reports any problems with the healing of the osteotomy. The results in our group of patients are comparable with the results published by other authors. CONCLUSION: Weil osteotomy allows a planned controlled shortening of metatarsal with a stable fixation. Osteotomy heals well. Osteotomy is intraarticular which on one side provides the possibility to correct dislocation in the MTP joint, however, on the other hand it poses a risk of the limitation of the range of motion of this joint. The main contribution the authors see in the new possibility of surgical treatment of more severe matatarsalgia and deformities of the forefoot with the preservation of joints.

[Indications for the cementless Zweymuller Bicon cup in acetabular fractures]. / Necementovaná jamka Zweymüller Bicon v indikaci po zlomenine acetabula.

PURPOSE OF THE STUDY: The aim of the study is an assessment of short-term results after the implantation of cementless Zweymüller Bicon cup in patients with a complicated anatomy after acetabular fractures. MATERIAL: The group of 10 patients indicated for Zweymüller cementless THR in post-traumatic osteoarthritis after acetabular fracture was selected of the total number of 703 primary implantations performed in 1998 and 1999 at the authors' Orthopaedic Department. The group includes patients treated conservatively as well as by means of open reduction and fixation. METHODS: For the evaluation we used Harris Hip Score and radiographic assessment based on radiographs in two projections on which signs of implant loosening and incidence of particular ossifications were monitored. RESULTS: Harris Hip Score was in 6 cases higher than 90 points, in 2 cases its value was 80 points. The low score in another 2 patients related to the limitation of the function resulting from the trauma and in one case from the injury of sciatic nerve during open reduction and fixation with a subsequent common peroneal nerve palsy. Radiographic check did not reveal any signs of loosening of the implant. Within the evaluation of particular ossifications the finding was 3 times classified in Group 1 and twice in Group 2. DISCUSSION: The number of patients of the authors' group corresponds with the numbers of patients presented in literature, however, due to a short time of the follow-up both clinical and radiographic results in our group are better. In all cases a good primary stability and position of the acetabular cup in the complicated anatomical conditions was obtained. Structural bone grafting was not necessary in any of the cases. Peroperative complications were not encountered. CONCLUSION: Short-term results of our small group of patients are very good. Both in the clinical and radiographic evaluation they correspond with the results of Zweymüller THR performed in patients with dysplastic acetabulum.

[The Zweymuller endoprosthesis in hip joint revision surgery]. / Endoprotéza typu Zweymüller v revizní chirurgii kycelního kloubu.

PURPOSE OF THE STUDY: The aim of the study is the verification of the applicability of the Zweymüller system of total hip replacement in dependence on the size of defects of acetabulum and femur and evaluation of early results in patients operated on in 1998 and 1999. MATERIAL: In 1998 and 1999 we reimplanted 125 total hip replacements. In 60 revision surgeries we used at least one component of Zweymüller Bicon Plus system. We prospectively followed defects of acetabulum and femur in DGOT classification. The size of the stem was planned, final indication of the cup was determined peroperatively. METHODS: During the implantation of the cup we tried to achieve primary stability of the implant. The cup was implanted in uni- and bisegmental defects. In total we implanted 50 Bicon cups, in 24 hip joints we applied morselized allograft in the defect. In tri-segmental defects we used twice the Burch Schneider cage and in 4 hip joints a bone allo-graft with a cemented cup in combination with SL-Plus stem. In one female patients after the implantation of Bicon cup in type 7 defect there occurred an early failure. When removing bone cement we preferred fenestration of the cortical bone of the femoral shaft. In 30 hips SL-Plus stem was used and in 13 hip joints SLR-Plus was applied. We checked 50 hip joints operated on by the method after Harris and by radiographs in two projections. RESULTS: Fifteen patients are without pain, 14 patients take analgesics. The final result is excellent in 24% of patients, good result in 32%, satisfactory in 24% and poor in 20% of patients followed up. By comparison with HHS value prior to the surgery HHS got worse in two patients who are not satisfied with the result of the operation. Average score prior to surgery was 47.4 points (range, 23-82.6). Five times we encountered a radioluscent line of acetabular component in zone III. Radiograph signs of loosening of the cup or stem were not found in any of the hip joints. CONCLUSION: Zweymüller system is applicable in revision surgeries of both cemented and cementless hip joint replacements. The cup may be applied in uni-segmental and bi-segmental acetabular defects under the condition of achievement of primary stability. Applied morselized bone allografts have a good potential for osteointegration and remodeling. The rectangular stem is suitable for the treatment of defects extending as far as 5 cm below the level of lesser trochanter. Bone cement was extracted from fenestration, transfemoral approach was not required in any of the patients. Even with the use of SLR (revision) stem we did not transfer fixation of the femoral component to the lower half of femur.

[Revision of total hip replacement operations at the Orthopedic Clinic IPVZ in Prague, 1999]. / Revizní operace TEP kycelního kloubu na Ortopedické klinice IPVZ v Praze v roce 1999.

PURPOSE OF THE STUDY: The aim of the work is to evaluate the results of revision surgeries of total hip replacements at the Orthopaedic Department IPVZ in 1999. MATERIAL: Revision surgery of 61 THR was performed at the Orthopaedic Department IPVZ in 1999. Most of them (54) were reoperated for aseptic loosening of the cup or both components, 4 patients for aseptic loosening of the stem, 1 patient was reoperated for recurring dislocation of THR and 2 patients for septic loosening. Eleven loosened 44/32 Poldi cups were reoperated on average after 160 months, twelv 49/32 Poldi cups on average after 143 months and seven 54/32 Poldi cups on average after 111 months. Sixteen loosened Walter Motorlet cups were reoperated on average after 111 months, 16 loosened Walter-Motorlet cups were revised on average after 83 months, 3 Martin cups on average after 112 months. Another 4 cementless cups of different provenance were reoperated in the interval of 9-54 months after the primary operation. METHODS: For the revision surgery we used 28 times Zweymüller Bicon cementless cup and in 26 hip joints Poldi cemented cup, in 6 patients we applied structural bone allografts, in 31 patients morselized allografts prepared on a bone mill. For the revision surgery of loosened stems we used in 18 patients Zweymüller SL Plus stem and in 7 patients Zweymüller SLR stem. DISCUSSION: From the viewpoint of long-term results THR implanted in patients with a secondary postdysplastic osteoarthritis is more risky than in the patients with a primary degenerative affection of the joint. It has been proved that also a cemented total hip replacement may bring good long-term results comparable with the results of some cementless implants. CONCLUSION: In most of the patients the primary diagnosis was postdysplastic osteoarthritis of the hip joint. Recently the need has started to grow for revision surgery in patients with loosened modern cementless implants. In revision surgeries the system of cementless THR of Zweymüller type proved suitable. The need for the application of bone allografts was quite frequent.

[Medium-term Experience with Zweymüller's Bicon Plus Cup in the Treatment of Postdysplastic Osteoarthritits of the Hip Joint.]. / Strednedobé zkusenosti s jamkou typu Zweymüller Bicon Plus v lécbe postdysplastické artrózy kycelního kloubu.

The authors retrospectively evaluate a group of 28 hip joints in which in 1995 and 1996 total hip replacement was performed for developmental dysplasia of the hip joint. They included in the study only patients with dysplasia of types B, C and D after Eftekhar. By means of the method after Ranawat and Pagnan they determine the ideal centre of the rotation of the hip join and the so called TAR-true acetabular region. They checked the patients in 1999 and evaluated subjective complaints, objective findings according to Harris Hip Score and x-ray findings on a radiograph of the pelvis and on the radiograph showing a 45 degrees rotation (the Judet view). In most hip joints operated on the actual centre of rotation differed from the ideal centre of rotation. Maximum difference was 18 mm. In the hip joints of type C they recorded more often a higher position of the centre of rotation (a higher placement of the cup). None of the patients was reoperated, radiographs did not show signs of aseptic loosening of the acetabular component. Zweymüller's Bicon Plus cup can be used also in cases of severe dysplasia of the hip joint. Primary stability of the implant and a good medium-term result can be achieved in most cases. The authors consider this type of implant especially suitable for patients with developmental dysplasia. Key words: total hip replacement, developmental dysplasia of the hip, Zweymuller's Bicon cup.

[Unicondylar replacement of the knee joint.]. / Unikondylární totální protéza kolenního kloubu.

Twenty-nine unicondylar replacements of the knee joint (UKR) of St. Georg type were implanted in 27 patients at the Orthopaedic Clinic IPVZ in the period between 1985-1994. The average age in case of females was 73 years, in case of men 71 years. The most frequent indication was osteoarthritis of the knee joint of varus type. Two patients (7 %) had to be reoperated on for aseptic loosening of the tibial component, on average 5,5 years after the surgery. Revision surgery for breaking of femoral component was performed in five cases, on average 6 years after the primary implantation. The authores evaluated 16 patients with UKR still in situ. In 8 patients the prosthesis is entirely painless, in 10 joints operated on the radiograph showed a developed femoropatelar osteoarthritis, osteoarthritic changes of the opposite compartment in 2 of them and a radioluscent line up to 1 mm in 3 cases. Despite a high frequency of late complications the authors consider UKR for an alternative to high supratubercular osteotomy of tibia in older patients, for a suitable method of the treatment of osteochondritis dissecans and Ahlbäck disease of the knee joint. The success of this operation is conditioned by a perfect surgical technique and implant of suitable design. Key words: replacement of the knee joint, aseptic loosening, fatique failure of material.

[ABG Cementless THR: Description of the Implant, Medium-term Results.]. / Necementovaná náhrada kycelního kloubu ABG: popis implantátu, strednedobé výsledky.

The authors present medium-term clinical results and radiographic evaluation of the implantation of cementless ABG total hip replacement. The implant is made from titanium alloy with a press-fit acetabular cup. The outer surface of the cup is coated with hydroxyapatite. Primary stability of the stem is guaranteed by its anatomical shape, secondary stability by the hydroxyapatite coating in the metaphyseal part of the implant. Evaluation covers a group of 19 patients who showed up to the clinical and radiographic follow-up. Average age at the time of implantation was 52 years (ranging between 31 and 65). The most frequent indication was in 11 cases primary coxarthrosis, in 5 cases necrosis of the head of the hip joint. Four times the operation was indicated for secondary postdysplastic osteoarthritis of the hip joint. Clinical results were evaluated according to Harris questionnaire. Excellent result was achieved in 10 patients (50 %), good result in 6 patients (30 %). Radiographic finding was evaluated on the basis of Gruen criteria using radiographs in 2 projections. The most frequent finding was a good secondary stability of the cup and metaphyseal stem with cortex hypotrophy in zones 2 and 6. In one case we encountered certain signs of loosening of acetabular cup. One THR was re-implanted due to aseptic loosening. Average period of follow-up was 4 years and 6 months. Key words: cementless THR, hydroxyapatite, pressfit principle.

[Cementless Femoral Revision THR after Wagner- Medium-term Results.]. / Necementovaná femorální revizní protéza kycelního kloubu podle Wagnera - strednedobé výsledky.

Authors report on a group of patients operated on in the period 1992-1994. In large bone defects of proximal femur a cementless revision stem of type Wagner was used. The group comprised 13 patients, the most frequent indication was septic loosening of THR handled by a two-phase procedure and aseptic loosening of both components using implants 265 and 306 mm long and with a diameter 14-22 mm. In 12 patients also the cup was revised. Nine patients were checked in 1999 by Harris Hip Score with one excellent result, two good results, three fair and three poor results. Radiograph proved bone ingrowth in all patients as well as secondary biological stabilization of the stem. No signs of stem loosening were found. In 7 patients the stem subsided by maximum 12 mm. The revision of the cementless stem can be considered in certain indications for an alternative of a mere extraction of the implant, i. e. resection arthroplasty with all functional consequences. Therefore the revision stem of type Wagner is still indicated in specific cases. Key words: THR, defects of femur, revision implant.

[Changes in Roughness of Exposed Head of POLDI Femoral Component.]. / Zmeny drsnosti exponované hlavice cementované totální endoprotézy kycelního kloubu POLDI.

The authors have examined the roughness of the heads of four exposed all-metal cemented femoral components of Poldi type using Talysurf 6 device. The results achieved were compared with the roughness of the not yet used head of Poldi femoral component. Both in the exposed and not used heads the Ra factor lower than the value reported in production documentation of the manufacturer. Even in a longterm exposition (17 years) there occurred no changes in the roughness of the metal head of the femoral component. Therefore it is possible in revision surgeries due to aseptic loosening of the acetabular component, to replace only the cup and leave the original stem in place. Key words: THR, femoral component, surface roughness.

[Long-term Results of TEP of the Hip Joint Poldi.]. / Dlouhodobé výsledky TEP kycelního kloubu Poldi.

The authors evaluate a group of 192 patients operated in 1983 at the Orthopaedic Clinic of the Institute for Postgraduate Medical Training to whom 196 cemented total endoprostheses of the hip joint type Poldi were implanted. Of these 53.1 % patients were operated on account of primary arthritis, 29.1 % on account of postdysplastic arthritis of the hip joint. In four patients conversion of an osseous ankylosis to an endoprosthesis was performed. In 59.7 % a medium Poldi socket was used, in 36.5 % a small Poldi socket and in 13.8 % a large Poldi socket. For fixation in all patients Palacos cement with first generation technique was used. In seven patients augmentation of a dysplastic acetabulum by an autogenous graft, as described by Harris, was made. The number of peroperative complications and technical errors does not exceed data in the literature. 15.8 % hip joints were re-operated - 0.5 % on account of a relapsing dislocation, 0.5 % because of early failure of the cement-bone bond due to bad cementing technique of the acetabular component, 1 % on account of late septic release, 0.5 % because of isolated aseptic release of the shank, 2.6 % because of aseptic release of both components and 10.7 % on account of aseptic release of the acetabular component, on average 8.3 years after surgery. Aseptic release of the socket correlates significantly with the size of the socket used and with the original diagnosis. The mean wear of the small socket is 0.22 mm per year, of the medium socket 0.28 mm per year and of the large socket 0.12 mm per year. Sockets of small size become released four times as frequently as medium and large ones and release is twice as frequent after surgery of secondary postdysplastic arhritis than after implantation on account of deforming arthritis of the hip joint. When evaluating the group of 60 hip joints according to HHS in 31.7 % excellent results were achieved, in 28.3 % good results, in 20 % satisfactory results and in 20 % poor results. The authors did not find a positive correlation between painfulness of the joint and signs of aseptic release of the socket on X-ray examination. Key words: TEP of the hip joint, aseptic release, bone cement, complications of TEP of the hip joint.

[Experience with Non-cemented Walter - Motorlet Endoprostheses of the Hip Joint.]. / Zkusenosti s necementovanou endoprotézou kycelního kloubu Walter - Motorlet.

In 1987-1994 at the Orthopaedic Clinic of the Institute for Postgraduate Medical Training 67 non-cemented total endoprostheses of the hip joint, type Walter-Motorlet were implanted. The authors submit the evaluation of 39 endoprostheses 30-102 months after operation (mean follow-up period 62.5 months). The investigation comprised 14 patients where by March 1997 reimplantation of one or both components was performed. The mean age of the patients at the time of operation was 49 years. Secondary postdysplastic arthritis was the indication in 53.9 %, primary arthritis in 23.1 %, necrosis of the neck of the femur in 10.3 %. In the general evaluation according to Harris excellent results were achieved in 43.6 %, good results in 25.7 %, satisfactory results in 17.8 % and unsatisfactory results in 12.9 %. As to subjective evaluation, a painless hip joint was reported only by 25.6 % of the patients, slight pain not restricting activity was reported by 41 %, pain which had to be mitigated by analgesics by 33.4 %. Certain X-ray signs of loosening were found in the area of the acetabular component in three patients, in the area of the femoral component in four patients. As compared with the hybrid combination Walter-Motorlet socket/Poldi shaft and as compared with evaluation of the Zweymüller endoprosthesis the results are worse as regards the number of aseptic loosenings and subjective evaluation by the patients. Key words: non-cemented endoprosthesis of the hip joint, aseptic loosening, reoperation of TEP of the hip joint.

[Complications of hinged endoprostheses of the knee joint, endomodell link.]. / Komplikace závesné endoprotézy kolenního kloubu Endomodell Link.

The authors implanted in 1985-1992 25 hinged endoprostheses of the knee joint, type Endomodell Link. It is a type of endoprosthesis which belongs into the group of so-called modified hinged prostheses. In addition to flexion and extension the design of the implant permits also 15 degree axial rotation. Indication for operation were deformities of the knee joint in 21 cases, re-operation in two knee joints and bony ankylosis associated with rheumatoid arthritis in two knee joints. The mean age of the patients was 64 years. In two patients infectious complications developed and the implant had to be removed. The authors did not record in any of the patients aseptic loosening with migration of the components or formation of radiolucencies. In one female patient the movable portion of the endoprosthesis broke of and after reimplantation of the damaged part 1.5 years later mechanical failure occurred due to wear of the thin-walled polyethylene capsule which caused laxity of the joint in the varus - valgus sense. During clinical check-up of the patients the authors found a similar condition - laxity of the knee joint in another 10 patients. It may be assumed that in these patients mechanical failure and the necessity of re-operation is only a question of time. Based on this experience the authors ceased to use this type of endoprosthesis. Key words: hinged prosthesis of the knee joint, mechanical failure.

[Experience with Non-cemented Endoprostheses (Walter-Motorlet) of the Hip Joint.]. / Zkusenosti s necementovanou endoprotézou kycelního kloubu Walter-Motorlet.

In 1987-1992 at the Orthopaedic Clinic of the IPVZ 61 non-cemented total endoprostheses of the hip joint Walter-Motorlet were implanted. The mean age of the patients is 50 years, the most frequent cause of operation is secondary postdysplastic arthritis of the hip joint (42.6%). In 1994 the authors evaluated the results, using Harris' method. The shortest follow up period is 12 months, the mean follow up period 29 months. In the subjective evaluation 23% of the patients report pain of the operated joint dependent on analgetics. In the general evaluation excellent or good results were recorded in 68.2%, satisfactory results in 20.5%, poor results in 11.3% of the patients. Roentgenological loosening of the socket was observed in three patients, the socket was, however, not reimplanted so far. Five patients were reoperated on account of aseptic loosening of the shank; reimplantation of a cemented shank Poldi was performed. In another three patients there are certain X-ray signs of loosening. So far failure of the femoral component occurred so far in eight patients. As compared with the hybrid combination Walter-Motorlet socket/Poldi shank the results are from the aspect of subjective evaluation by the patients as well as with regard to the number of aseptic loosenings worse when non-cemented prostheses are used. Key words: non-cemented endoprosthesis of the hip joint, aseptic loosening, reoperation of TEP of the hip joint.

[Experience with hybrid hip prosthesis walter-motorlet/poldi.]. / Zkusenosti s hybridní endoprotézou kycelního kloubu Walter-Motorlet/Poldi.

In 1987-1992 at the Orthopaedic Clinic IPVZ 108 hybrid endoprostheses of the hip joint, type Walter-Motorlet/Poldi were implanted (non-cemented socket Walter-Motorlet, cemented shank Poldi). The authors submit evaluations of 75 endoprotheses made 2-7 years after surgery (mean follow-up period 3 and a half years). The mean age of the patients was 49 years (range 39-62 years), the most frequent preoperative diagnosis was secondary postdysplastic coxarthrosis (52%), other diagnoses were primary coxarthrosis (24%), idiopathic necrosis of the head of the femur (20%) and posttraumatic coxarthrosis (4%). Genneral evaluation according to Harris revealed excellent results in 6% of the patients and unsatisfactory results in 1% of the patients. Subjective evaluation of the painfulness revealed a painless hip joint in 56%, mild occasional pain was reported by 30% of the patients and mild pain which can be mitigated by aspirin was recorded in 14% of the patients. The prosthesis became loosened in one patient bilaterally - it was a case of poor indication of a total endoprosthesis of the hip joint in a patient with a metabolic disorder and osteopathy. The general incidence of paraarticular ossifications was 17%. Comparison of the results with a similar group of patients with non-cemented total endoprostheses Walter-Motorlet, the results obtained with hybrid total endoprostheses are better from the subjective and objective aspect. Key words: hybrid total endoprosthesis of the hip joint, aseptic loosening.

[Cementless Endoprosthesis of the Hip Joint ABG: Description of the Implant, Operation Technique.]. / Bezcementová endoprotéza kycelního kloubu ABG: popis implantátu, operacní technika.

A non-cemented endoprosthesis of the hip joint ABG is producet by Howmedica Co. from a titanium alloy. The socket is hemispherical, primarily anchored according to the press fit principle. The external surface of the annulus is covered by a layer of hydroxyapatite. The shape of the shank is anatomical, it respects the anterior curvature of the femur and the anteversion of the neck of the femur. Its primary stability is ensured by the shape of the shank, the secondary stability is achieved in the process of osteoinduction in the metaphyseal part covered by hydroxyapatite. Between 1992 and 1994 18 hip joints were operated. No peroperative nor postoperative complications were observed, the short-term results are very good. With regard to the short follow-up time, long-term clinical results will be the subject of subsequent papers. Key words: non-cemented endoprosthesis of the hip joint, press fit principle, hydroxyapatite, osteoinduction.

[Experience with non-cemented stems in Schenker hip prosthesis]. / Zkusenosti s necementovaným dríkem kycelní endoprotézy typu Schenker.

In 1986-1988 at the Orthopaedic clinic of the Institute for Postgraduate Medical Training 56 stems on non-cemented total endoprostheses of the hip joint type Schenker were implanted. The non-cemented stem was combined in all patients with a cemented socket Poldi. The endoprosthesis was indicated in particular in young patients in 59% in hip joints affected with secondary postdysplastic arthritis of the hip joint. The group was checked by Harris' method, the mean follow-up period in 1992 was 58 months. Of 36 followed up patients 21 operated patients reported pain in the area of the hip joint, 10 patients used analgetics. In nine patients reimplantation of the non-cemented Schenker stem was performed on account of aseptic loosening, in 11 patients the X-ray check revealed obvious signs of aspectic loosening associated with subjective complaints. The dependence of aseptic loosening on the quality of primary implantation is marked. In patients with perfect cortical contact of the stem aseptic loosening developed in 27% of the patients, in patients with inadequate cortical contact aseptic loosening was recorded in 80% of the operated patients. The general evaluation according to Harris comprised 42% excellent results, 30% good results, 14% satisfactory results and 14% poor results. This evaluation does not include patients who on account of pain and loosening of the femoral Schenker component were already re-operated. Because of the considerable number of complications implantation of this type of prosthesis was discontinued at the authors' department.

[Causes of corrosive mechanical defects in isoelastic endoprostheses]. / Príciny korozne mechanických poruch izoelastických endoprotéz.

Within the framework of evaluation of endoprostheses of the hip joint reoperated at the orthopaedic clinic of the Institute for Postgraduate Medical Training, Faculty Hospital Na Bulovce in Prague in the course of six years the authors made a more detailed analysis of the group of isoelastic POLDI endoprostheses which displayed obvious signs of corrosion. The specimens from this group were subjected to evaluation focused on corrosion, metallographic and fractographic evaluation. In impaired wires of isoelastic endoprostheses the fracture surfaces have a fatigue character where a corrosion fatigue mechanism may be assumed as well fracture with a dominant mechanical component of stress. From the analysis of corrosion ensues that the connections of the wire shank with the head of the endoprosthesis are affected by crevice corrosion, the revealed fractures and cracks are most probably associated with corrosion fatigue. The construction of isoelastic prostheses of this type is the cause of corrosion processes which lead to mechanical failure. This should be the reason to refuse them for patients of any age group.

[Noncemented revision of femoral hip joint prostheses with severe bone defects (preliminary report)]. / Necementovaná femorální revizní protéza kycelního kloubu pri tezkých kostních defektech (predbezné sdelení).

The authors present an account of their initial experience with Wagner's non-cemented femoral revision prosthesis of the hip joint. After a brief technical description of the implant the mention the indications and contraindications of they revision shaft. They emphasize the necessity of peroperative planning and describe the surgical technique. Since 1992 they used a revision shaft in five patients (three times in aseptic loosening of a TEP of the hip joint, once during septic loosening and once when treating a periprosthetic fracture with extensive bone destruction). Long-term experience will be the subject of a subsequent paper.