Pros and cons of total hip arthroplasty with metaphyseal Proxima endoprosthesis

PRACE ORYGINALNE Waldemar WRAŻEŃ 1 Edward B. GOLEC 1,2 Krzysztof A. TOMASZEWSKI 1,3 Piotr GOLEC 1 Michał de LUBICZ JAWOROWSKI1 Zbigniew DUDKIEWICZ 4 Pros and cons of total hip arthroplasty with metaphyseal Proxima endoprosthesis Blaski i cienie alloplastyki całkowitej stawu biodrowego endoprotezą przynasadową typu Proxima 1 Klinika Chirurgii Urazowej i Ortopedii, 5 Wojskowy Szpital Kliniczny z Polikliniką Samodzielny Publiczny Zakład Opieki Zdrowotnej, Kraków Kierownik: Prof. dr hab. med. Edward B. Golec 2 Zakład Rehabilitacji w Ortopedii, Katedra Rehabilitacji Klinicznej, Wydział Rehabilitacji Ruchowej, Akademia Wychowania Fizycznego im. Bronisława Czecha, Kraków Kierownik: Prof. dr hab. med. Edward B. Golec 3 Katedra Anatomii, Uniwersytet Jagielloński Collegium Medicum w Krakowie Kierownik: Prof. dr hab. med. Jerzy A. Walocha 4 Klinika Chirurgii Ręki, Katedra Ortopedii i Traumatologii, Uniwersytet Medyczny w Łodzi Kierownik: Dr hab. med. Zbigniew Dudkiewicz prof. nadzw. Dodatkowe słowa kluczowe: alloplastyka całkowita stawu biodrowego endoproteza typu Proxima Additional key words: total hip arthroplasty Proxima endoprosthesis Praca finansowana ze środków własnych. Adres do korespondencji: Edward Golec Klinika Chirurgii Urazowej i Ortopedii 5 Wojskowego Szpitala Klinicznego z Polikliniką SP ZOZ ul. Wrocławska 1-3, 30-901 Kraków Tel.: 12-630 82 02 lub 203 Fax: 12-632 53 01 e-mail: bgolec@poczta.onet.pl The authors present their own experience concerning total hip arthroplasty with the metaphyseal prosthesis Proxima. Proxima, a metaphyseal prosthesis, provides an innovative supplement to total hip arthroplasty. In this study, the authors present their own experience using Proxima in patients with hip osteoarthritis. This study was performed between 2008 to 2013 and comprised of 62 patients, of which 38 were male (61.3%) and 24 female (38.7%). All patients were operated on due to hip osteoarthritis using total hip arthroplasty with the metaphyseal prosthesis Proxima. The age of patients included into the study ranged from 23 years to 62 years with the mean age of 46 years. The authors paid close attention to the pros and cons of surgical techniques and assessed clinical and radiological results in both the short and long term observation periods. The clinical evaluation was based on the Harris Hip Score and radiological assessment of fixation of the acetabular cup of the endoprosthesis was based on Pradhan s criteria. The endoprosthesis Proxima stem was positioned using the manufacturer s recommended method, evaluating the direction, scope and duration of the displacement in the marrow cavity of the proximal stump of the femur. According to the authors analysis, the surgery gives good functional and radiological results both in the shortand long-term observation periods. The effectiveness depends on precise qualification for surgery, proper surgical techniques and specific anatomical conditions of the proximal femur stump. The most common reasons for primary and secondary dislocations of the metaphyseal endoprosthesis Proxima stem occur during the first three months post surgery. This is due to incorrect surgical techniques, which disregard the importance of specific anatomical conditions of the proximal femoral stump, which affects Proxima implantation, and cause deviations towards a varus or valgus orientation. Autorzy pracy prezentują doświadczenia własne w alloplastykach całkowitych stawu biodrowego endoprotezą przynasadową typu Proxima. Dokonują tego w oparciu o materiał badań obejmujący lata od 2008 do 2013 roku, który stanowi 62 pacjentów operowanych z powodu zwyrodnienia stawu biodrowego metodą alloplastyki całkowitej endoprotezą typu Proxima, w tym 38 mężczyzn (61,3%) oraz 24 kobiety (38,7%). Wiek włączonych do badania wahał się w granicach od 23 do 62 roku życia dając średnią 46 lat. Autorzy zwracają uwagę na blaski i cienie techniki operacyjnej oraz dokonują oceny wyników klinicznych i radiologicznych we wczesnym i odległym okresie obserwacji. Ocena wyników klinicznych została oparta o czynnościowe kryteria Harrisa. Wyniki radiologiczne osadzenia panewki endoprotezy oparto o kryteria Prandhana, a trzpienia na kryteriach własnych oceniających kierunek, zakres i czas jego przemieszczenia się w jamie szpikowej kikuta końca bliższego kości udowej. Zdaniem autorów pracy analizowany zabieg operacyjny skutkuje zarówno w obserwacji wczesnej jak i odległej bardzo dobrymi i dobrymi wynikami czynnościowymi oraz radiologicznymi. Jego skuteczność zależy od prawidłowej kwalifikacji do zabiegu operacyjnego, przekonującej techniki operacyjnej oraz od szczególnych warunków anatomicznych kikuta końca bliższego kości udowej. Przyczyn pierwotnego i wtórnego przemieszczenia się trzpienia endoprotezy w łożysku kostnym w kierunku na szpotawość lub koślawość, które ma miejsce w pierwszych trzech miesiącach od wykonania zabiegu operacyjnego, upatrują w nieprawidłowej technice operacyjnej ze zlekceważeniem znaczenia szczególnych warunków anatomicznych kikuta końca bliższego kości udowej do jego implantacji. Przegląd Lekarski 2015 / 72 / 7 335

Introduction Arthroplasties of various kinds and configurations are a widely accepted and continuously developing method for dealing with advanced degenerative changes in the hip joints. To perform them, the following implants are used: cemented [1,2], cementless [3], hemiprosthesis [4,5], primary prosthesis [6], revision prosthesis [7,8], prosthesis with bispheric head [9] and with short stem [10,11]. The basis for qualification of patients for these operations, which are often extensive and technically difficult to perform, is to eliminate or significantly decrease pain in the affected hip joint, and also to reduce various types of contractures, restore the equal leg length, improve gait efficiency, stereotype and aesthetics and thereby to improve their quality of life [12]. In recent years, there has been a decrease in the age of patients who are considered eligible for the aforementioned procedures. This is possible due to the continuous introduction of modern prostheses into clinical practice, for example porous-coated, hydroxyapatitecoated [13] and short stem metaphysealfitting prostheses [14-16]. Aim The aim of this work is to evaluate the results of total hip-replacement arthroplasty with the metaphyseal prosthesis Proxima in the early and late observation periods, including answering the following questions: 1. What are the functional and radiological results of total hip replacement with the metaphyseal prosthesis Proxima in the early and late observation periods? 2. What determines the effectiveness of the metaphyseal prosthesis Proxima stem implantation into the marrow cavity of the proximal femoral stump at obtaining its primary and secondary stabilization? 3. What are the reasons for and direction of primary and secondary displacement of the of the metaphyseal prosthesis Proxima stem implantation into the marrow cavity of the proximal femoral stump and in which observation period does it take place most commonly? Material and methods The aim of this study was realized on the basis of the research material originating from the Traum Surgery and Orthopedics Department of the 5th Military Clinical Hospital with Polyclinic in Krakow, covering the period between 2008 and 2013. It comprised of 62 patients, of which 38 were male (61.3%) and 24 were female (38.7%), who were operated on due to hip joints degeneration by the total hip arthroplasty method with the metaphyseal prosthesis Proxima. The age of patients included in the study ranged from 23 to 62 years with a mean age of 46 years. Only one man was 23 years of age and only one woman was 62 years of age. The rest of the operated on was 42-54 years old. The most common etiology for hip was idiopathic, and was observed in 53 patients (85.5%), of which 37 were male (59.7%) and 16 were female (25.8%) (Tab. I). Table I Etiology of the hip in operated patients. Etiologia zwyrodnienia stawów biodrowych u operowanych pacjentów. Etiology of the hip joint degeneration Male All patients qualified for the analyzed surgery were operated on using a posterolateral approach. In the perioperative period, all patients were administered drugs for anti-inflammatory prophylaxis (Tarcefandol, Zinacef, Metronidazol, Fortum) and anti-thromboembolic drugs (Clexane, Fraxiparyna) for 6 to 8 weeks, starting from the day of the surgery. A suction drain from the surgical wound to the Redon bottle was maintained until the second postoperative day. During this period, patients required transfusion of 2-4 units of RBC (PRBCs) and 1-2 units of frozen plasma (FP). Patients who underwent the surgery stood up on the 2 nd or 3 rd postoperative day, and was preceded by sitting upright on the side of the bed with legs over Sex Female Total number % Number % number % degeneration 37 59.7 16 25.8 53 85.5 Post-traumatic degeneration 1 1.6 - - 1 1.6 Developmental dysplasia - - 8 12.9 8 12.9 Total 38 61.3 24 38.7 62 100 Table II Score ranges in Harris Hip Score. Zakresy punktowe skali Harrisa. Results Table III Point ranges of analyzed variables. Zakresy punktowe analizowanych zmiennych. Point range Very good 90 100 Good 80 89 Satisfactory 70 79 Poor < 70 Analysed variable Points in total Pain of hip joint 44 Function of hip joint 47 Range of motion of hip joint 5 Absence of deformity 4 Total 100 Table IV Pain assessment according to Harris Hip Score (Maximum = 44 points). Ocena dolegliwości bólowych wg skali Harrisa maksymalnie 44 punkty. Type of pain Characteristics of pain Points None Not applicable 44 Slight pain Mild pain Moderate pain Marked pain Sporadic pain or awareness of low-intensity pain without a significant impact on daily activities. No effect on average activities, rarely moderate pain with unusual activity; may take aspirin. Some limitation of ordinary activity or work. May require occasional pain medication stronger than aspirin. Severe pain occurs everyday, significantly limiting daily activities. Patient is taking strong analgesics. Totally disabled Severe pain is forcing patient to take lying position. 0 the edge with knees and hip joints bent. Over 4 or 5 days, patients started learning how to walk, initially with the assistance of a walker or elbow crutches, to avoid burdening the limb. Gradual and controlled limb burdening started 3 weeks after implantation of the hip endoprosthesis. Initially, weight bearing did not exceeding 20% of patient s body weight. The surgeries were not complicated by local or systemic complications. Owing to the fact that the short-stem endoprosthesis Proxima was the first of metaphyseal endoprostheses implanted in our Clinics, patients selected for this surgery remained under detailed observation. The following procedures and exami- 40 30 20 10 336 W. Wrażeń et al.

Table V Daily activity assessment according to Harris Hip Score (Maximum = 14 points). Ocena czynności życiowych wg skali Harrisa maksymalnie 14 punktów. Activity Characteristics of activity Points Stairs Normally without using a railing 4 Normally using a railing 2 In any manner 1 Unable to do stairs 0 Public transportation Able to use transportation 1 Sitting Putting on shoes and socks Comfortably, ordinary chair for one hour 5 On a high chair for 30 minutes 3 Unable to sit comfortably on any chair 0 With ease 4 With difficulty 2 Unable 0 Table VI Gait efficiency assessment according to Harris Hip Score (Maximum = 33 points). Ocena wydolności chodu wg skali Harrisa maksymalnie 33 punkty. Gait efficiency - claudication Points Gait without claudication 11 Gait with slight claudication 8 Gait with moderate claudication 5 Gait with pronounced claudication 0 Gait with no assistance of cane or crutches 11 Gait with assistance of cane or crutches, long walks 7 Gait with assistance of cane, full time 5 Gait with assistance of a crutch, full time 3 Gait with assistance of 2 canes 2 Gait with assistance of 2 crutches 0 Unable to walk 0 Table VII Distance walked according to Harris Hip Score. Ocena długości pokonywanego dystansu wg skali Harrisa. Distance walked Points Unlimited 11 6 blocks or 30 min (600-1000m) 8 2-3 blocks or 10-15 min (200 400 m) 5 Indoors only 2 Bed and chair only 0 Table IX Absence of deformity according to Harris Hip Score [17] (Maximum = 4 points). Ocena braku kalectwa wg skali Harrisa [17] maksymalnie 4 punkty. Examined variable Contracture degree Points Fixed flexion contracture Fixed abduction Fixed internal rotation in extension Limb length discrepancy < 30 o 1 > 30 o 0 < 10 o 1 > 10 o 0 < 10 o 1 > 10 o 0 < 3.2 cm 1 > 3.2 cm 0 Table VIII Range of hip joint motion according to Harris Hip Score (Maximum = 5 points). Ocena zakresu ruchomości stawu biodrowego wg skali Harrisa maksymalnie 5 punktów. Motion Flexion Abduction External Rotation Internal Rotation Adduction Table X Results obtained in males qualified for total hip arthroplasty Proxima depending on degeneration etiology. Wyniki uzyskane u mężczyzn zakwalifikowanych do alloplastyki całkowitej stawów biodrowych endoprotezą przynasadową typu Proxima w zależności od etiologii zwyrodnienia. Etiology of hip Post-traumatic Fair Poor Total Numbe % Number % Number % 32 84.2 5 13.2 37 97.4 74 67 Not applicable - - 1 2.6 1 2.6-65 Not applicable Total 32 84.2 6 15.8 38 100 Range of motion Motion arch Index Points 0 45 o 45 o 1.0 45 46 90 o 45 o 0.6 27 91 110 o 20 o 0.3 6 111-130 o 20 o 0.0 0 0 15 o 15 o 0.8 12 16 20 o 5 o 0.3 15 21 45 o 25 o 0.0 0 0 15 o 15 o 0.4 6 > 15 o Not applicable 0.0 0 Not applicable Not applicable 0 0 15 o 15 o 0.2 3 > 15 o Not applicable 0.0 0 nations were performed in each patient scheduled to undergo surgery: 1. Medical history, general physical examination and orthopedic examination of the local state and x-ray of both hip joints in anteroposterior (AP) view was performed. 2. Harris Hip Score [17] was used in patients between the 10th and 14th days prior to scheduled surgery and 3, 6 and 12 months postoperatively. Parameters in Harris Hip Score include assessment of subjective and objective indicators. The objective ratings analyze the functional efficiency of the moving joint and subjective ratings analyze patient pain. These results are then analyzed using ranges of points which correspond to excellent, good, fair and poor (Tab. II). The Harris Hip Score evaluates pain and function of the hip joint, the scope of its mobility, and the extent of its disability (Tab. III-IX). Assessment of the range of motion of the hip joint is based on the angle values of a single motion arch, and is multiplied by index. The in total is multiplied by Przegląd Lekarski 2015 / 72 / 7 337

Figure 1 Radiological determination of endoprosthesis Proxima stem position in marrow cavity of proximal stump of femur using the authors own method correct position. Wyznaczenie radiologiczne położenia trzpienia endoprotezy typu Proxima w jamie szpikowej kikuta końca bliższego kości udowej lewej metodą własną położenie prawidłowe. Figure 2 Radiological determination of endoprosthesis Proxima stem position in marrow cavity of proximal stump of femur using authors own method Varus position. Wyznaczenie radiologiczne położenia trzpienia endoprotezy typu Proxima w jamie szpikowej kikuta końca bliższego kości udowej lewej metodą własną położenie szpotawe. Figure 3 Radiological determination of endoprosthesis Proxima stem position in marrow cavity of proximal stump of femur using authors own method Valgus position. Wyznaczenie radiologiczne położenia trzpienia endoprotezy typu Proxima w jamie szpikowej kikuta końca bliższego kości udowej lewej metodą własną położenie koślawe. 0.05 to get a point value (maximum 5 points) necessary for general evaluation. 3. Radiological examination of both hip joints in antero-posterior view, was performed 3 days postoperatively and 1, 3, 6 and 12 months. 4. On radiographs of the operated hip joints, lines characterizing the position of the endoprosthesis stem in the marrow cavity of the proximal stump of femur were traced, including the varus or valgus displacement, namely: a/ lines tangent to the external cortical outline of the proximal femoral stump - line A and line B, b/ line perpendicular to lines A and B, running at the level of the base of the vertical part of endoprosthesis stem - line C, c/ line perpendicular to line C, running through the apex of the proximal part of the stem, and in the middle of its conus line D. The course of line D, running perpendicular to line C, through the center of the cone of the endoprosthesis stem and parallel to lines A and B, was considered a correct location and a good radiological (Fig. 1). Varus displacement of line D, but without leaning of the cone of the endoprosthesis stem against cortical bone of the femur was considered an acceptable radiological (Fig. 2). Varus or valgus displacement of line D with the cone of the endoprosthesis stem leaning against cortical bone of the femur, was considered an unacceptable radiological (Fig. 3). Radiological assessment of fixation of the acetabular cup, according to Pradhan s criteria [18]. Statistical analysis Statistical analysis was performed Table XI in males 3 months after the total hip arthroplasty with endoprosthesis Proxima depending on etiology of the hip. Wyniki uzyskane u mężczyzn po 3 miesiącach od wykonania alloplastyki całkowitej stawów biodrowych endoproteza Post-traumatic using Statistica 10 PL software. Elements of descriptive statistics were used (mean, percentage distribution). The Students t-test and the Mann-Whitney U test were used as appropriate, to assess continuous variables. A p<0.05 was considered statistically significant. Results in males in males qualified for the total hip arthroplasty with endoprosthesis Proxima depending on etiology of the hip. In males qualified for the total hip arthroplasty basing on the Harris Hip Score, the results are as follows: fair results were reported in 32 males (84.2%) with a mean value of 74 points; poor results in 5 males (13.2%) with a mean value of 67 points; 1 male (2.6%), who was diagnosed with post-traumatic hip 3 7.9 29 76.3 5 13.2 37 97.4 91 84 77 Not applicable - - 1 2.6 - - 1 2.6-85 - Not applicable Total 3 7.9 30 78.9 5 13.2 38 100 had 65 points, which was a poor result (Tab. X). in males 3 months after the total hip arthroplasty with endoprosthesis Proxima depending on the etiology of the hip joint degeneration. Three months after the total hip arthroplasty Proxima, due to the idiopathic degeneration, excellent results were reported in 3 males (7.9%) with a mean value of 91 points, good results in 29 (76.3%) with a mean value of 84 points and fair results in the other 5 (13.2%), who obtained an average score of 77 points. One man (2.6%) who was operated on due to post-traumatic degeneration, had a good result (85 points) (Tab. XI). in males 6 months after the total hip arthroplasty with endoprosthesis Proxima 338 W. Wrażeń et al.

depending on the etiology of the hip joint degeneration. Six months after the total hip arthroplasty Proxima due to the idiopathic degeneration, excellent results were reported in 11 males (29%) with the mean value of 93 points, good results in 23 (60.5%) with the mean value of 85 points and fair results in the other 3 (7.9%), who obtained an average score of 77 points. 1 man (2.6%) who was operated on due to the post-traumatic degeneration had a good result (86 points) (Tab. XII). in males 12 months after the total hip arthroplasty with endoprosthesis Proxima depending on the etiology of the hip joint degeneration. Twelve months after the total hip arthroplasty excellent results were reported in 19 males (50%) with a mean value of 95 points, good results in 17 (44.8%) with a mean value of 85 points and fair results in 1 patient (2.6%), who obtained 73 points. 1 man (2.6%), who was operated on due to post-traumatic degeneration, had a good result (86 points) (Tab. XIII). in females in females qualified for the total hip arthroplasty with endoprosthesis Proxima depending on the etiology of the hip. In females qualified for the total hip arthroplasty basing on the Harris Hip Score, fair results were reported in 9 of them (37.5%) with a mean value of 71 points and poor results in 7 of them (29.2%) with a mean value of 63 points. In females who were diagnosed with developmental dysplasia 2 (8.3%) had fair results with an average score of 73 points. The remaining 6 (25%) had poor results with an average score of 61 points (Tab. XIV). in females 3 months after the total hip arthroplasty with endoprosthesis Proxima depending on etiology of the hip. Three months after the total hip arthroplasty excellent result was reported in only 1 female (4.2%) who obtained 92 points, good results in 12 females (50.0%) with a mean value of 84 points and fair results in 3 patients (12.5%) with an average score of 76 points. In women who were operated on due to developmental dysplasia, 1 (4.2%) had an excellent result equalling 93 points, 5 (20.8%) had a good result with the mean value of 84 points and 2 (8.4%) had a fair result with a mean value of 75 points (Tab. XV). in females 6 months after the total hip arthroplasty with endoprosthesis Proxima depending on etiology of the hip. Six months after the total hip arthroplasty Table XII in males 6 months after the total hip arthroplasty with endoprosthesis Proxima depending on the etiology of the hip. Wyniki uzyskane u mężczyzn po 6 miesiącach od wykonania alloplastyki całkowitej stawów biodrowych endoproteza Post-traumatic Proxima due to the idiopathic degeneration, excellent results were reported in 8 females (33.3%) who obtained an average score of 94 points, good results in 6 females (25.0%) with a mean value of 86 points and fair results in 2 patients (8.4%) with an average score of 76 points. In women who were operated on due to developmental dysplasia, 3 (12.5%) had an excellent result with a mean value Harris Hip Score Results 11 29 23 60.5 3 7.9 37 97.4 93 85 77 Not applicable - - 1 2.6 - - 1 2.6-86 - Not applicable Total 11 29 24 63.1 3 7.9 38 100 Table XIII in males 12 months after the total hip arthroplasty with endoprosthesis Proxima depending on the etiology of the hip. Wyniki uzyskane u mężczyzn po 12 miesiącach od wykonania alloplastyki całkowitej stawów biodrowych endoproteza Post-traumatic 19 50 17 44.8 1 2.6 37 97.4 95 85 73 Not applicable - - 1 2.6 - - 1 2.6-86 - Not applicable Total 19 50 18 47.4 1 2.6 38 100 Table XIV Results obtained in females qualified for total hip arthroplasty Proxima depending on the degeneration etiology. Wyniki uzyskane u kobiet zakwalifikowanych do alloplastyki całkowitej stawów biodrowych endoprotezą przynasadową typu Proxima w zależności od etiologii zwyrodnienia. Developmental dysplasia Fair Poor Total Number % Number % Number % 9 37.5 7 29.2 16 66.7 71 63 Not applicable 2 8.3 6 25 8 33.3 73 61 Not applicable Total 11 45.8 13 54.2 24 100 equaling 93 points and 5 (20.8%) had a good result with the mean value of 86 points (Tab. XVI). in females 12 months after the total hip arthroplasty with endoprosthesis Proxima depending on etiology of the hip. Twelve months after the total hip arthro- Przegląd Lekarski 2015 / 72 / 7 339

Table XV in females 3 months after the total hip arthroplasty with endoprosthesis Proxima depending on etiology of the hip. Wyniki uzyskane u kobiet po 3 miesiącach od wykonania alloplastyki całkowitej stawów biodrowych endoproteza Developmental dysplasia plasty excellent results were reported in 11 females (45.8%) who obtained an average score of 93 points, good results in 4 females (16.7%) with a mean value of 86 points and fair result in 1 patient (4.2%) with an average score of 71 points. In women who were operated on due to developmental dysplasia, 3 (12.5%) had an excellent result with a mean value of 94 1 4.2 12 50 3 12.5 16 66.7 92 84 76 Not applicable 1 4.2 5 20.8 2 8.4 8 33.3 93 84 75 Not applicable Total 2 8.4 17 70.7 5 20.9 24 100 Table XVI in females 6 months after the total hip arthroplasty with endoprosthesis Proxima depending on etiology of the hip. Wyniki uzyskane u kobiet po 6 miesiącach od wykonania alloplastyki całkowitej stawów biodrowych endoproteza Developmental dysplasia 8 33.3 6 25 2 8.4 16 66.7 94 86 76 Not applicable 3 12.5 5 20.8 - - 8 33.3 93 86 - Not applicable Total 11 45.8 11 45.8 2 8.4 24 100 Table XVII in females 12 months after the total hip arthroplasty with endoprosthesis Proxima depending on etiology of the hip. Wyniki uzyskane u kobiet po 12 miesiącach od wykonania alloplastyki całkowitej stawów biodrowych endoproteza Developmental dysplasia 11 45.8 4 16.7 1 4.2 16 66.7 93 86 71 Not applicable 3 12.5 5 20.8 - - 8 33.8 94 86 - Not applicable Total 14 58.3 8 37.5 1 4.2 24 100 points and 5 (20.8%) had a good result with the mean value of 86 points (Tab. XVII). Radiological s of metaphyseal endoprosthesis Proxima stem seating based on the examination in antero-posterior view. Radiological s of metaphyseal endoprosthesis Proxima stem seating obtained in males. Based on the radiological examination in the antero-posterior view, 3 days after total hip arthroplasty Proxima, good results were obtained in 35 males (92.1%) and acceptable in 3 of them (7.9%). One month after the surgery, results were exactly the same. Three months after the surgery, good results were observed in 34 operated men (89.5%), acceptable in 1 of them (2.6%) and unacceptable in 3 (7.9%). In the 6 month observation period, results remained good in 34 males (89.5%), but the other 4 (10.5%) had unacceptable. Results observed after 12 months were identical to those obtained after 6 months (Tab. XVIII). Radiological s of metaphyseal endoprosthesis Proxima stem seating obtained in females. Based on radiological examination in the antero-posterior view, 3 days after total hip arthroplasty Proxima, good results were obtained in 20 females (83.3%) and acceptable in 4 of them (16.7%). One month after the surgery, 19 operated women (79.2%) had good s, 4 - acceptable s (16.7%) and 1 - unacceptable (4.1%). Three months after surgery, good results were observed in 17 women (70.9%), acceptable in 5 (20.9%) and unacceptable in 2 (8.2%). After 6 months of observation, good results were reported in 17 female patients (70.9%), acceptable in 4 of them (16.7%) and unacceptable in 3 (12.4%). Results observed after 12 months were identical to those obtained after 6 months (Tab. XIX). Radiological s of endoprosthesis stem seating obtained in the study group - females and males in total. The summary of radiological s of Proxima endoprosthesis stem seating in females and males in total in the third postoperative day are all follows: good s were observed in 55 patients (88.7%) and acceptable s in 7 of them (11.3%). After one month, good s were observed in 54 patients (87.1%), acceptable s in 7 of them (11.3%) and unacceptable in 1 of those who underwent the surgery (1.6%). Three months later, good s were reported in 51 patients (82.3%), acceptable in 6 (9.7%) and unacceptable in 5 (8%). In the 6 month observation period, there were 51 good s in the study group, 4 acceptable (6.4%) and 7 unacceptable (11.3%). These results were identical to those obtained in the 12 month observation period (Tab. XX). Valgus orientation of endoprosthesis stem was noticed only in 2 operated patients (8.2%). This displacement took place in the first 3 months after surgery. Radiological results of fixation of the acetabular cup of metaphyseal endoprosthesis Proxima obtained in the study group. Assessment of the radiological results of fixation using Pradhan s criteria, showed the correct location of the acetabular cup of metaphyseal endoprosthesis Proxima both in males and females in subsequent observation periods [18]. 340 W. Wrażeń et al.

Table XVIII Radiological s of endoprosthesis stem seating obtained in males. Wyniki radiologiczne osadzenia trzpienia endoprotezy uzyskane u mężczyzn. Endoprosthesis stem seating radiological result Correct - good Incorrect varus or valgus, without leaning of the cone of the endoprosthesis stem against cortical bone of the femur acceptable Incorrect varus or valgus, with leaning of cone of the endoprosthesis stem against cortical bone of the femur unacceptable Results of statistical analysis Statistical analysis of results obtained using the Harris Hip Score There was no statistically significant difference in the preoperative results of the Harris Hip Score between males and females with idiopathic hip joints degeneration (p>0.05). The severity of degeneration, grouped according to (fair in men vs. fair in women and poor in men vs. poor in women) also did not differ significantly from each other (p>0.05). After 3 months post surgery, there was a statistically significant improvement of (in comparison to preoperative assessment), both females (p <0.001) and males (p<0.001). These results apply to people with idiopathic etiology of osteoarthritis of the hip, and also to women diagnosed with developmental dysplasia Observation period 3 days 1 month 3 months 6 moths 12 months number % number % number % number % number % 35 92.1 35 92.1 34 89.5 34 89.5 34 89.5 3 7.9 3 7.9 1 2.6 - - - - - - - - 3 7.9 4 10.5 4 10.5 Total 38 100 38 100 38 100 38 100 38 100 Table XIX Radiological s of endoprosthesis stem seating obtained in females. Wyniki radiologiczne osadzenia trzpienia endoprotezy uzyskane u kobiet. Endoprosthesis stem seating radiological result Correct - good Incorrect varus or valgus, without leaning of cone of the endoprosthesis stem against cortical bone of the femur acceptable Incorrect varus or valgus, with leaning of cone of the endoprosthesis stem against cortical bone of the femur unacceptable Observation period 3 days 1 month 3 months 6 months 12 months number % number % number % number % number % 20 83.3 19 79.2 17 70.9 17 70.9 17 70.9 4 16.7 4 16.7 5 20.9 4 16.7 4 16.7 - - 1 4.1 2 8.2 3 12.4 3 12.4 Total 24 100 24 100 24 100 24 100 24 100 (p<0.001). Six months after surgery, Harris Hip Score results increased significantly, both in males and females, in comparison to evaluation after 3 months (p<0.01) and also when compared with the preoperative assessment (p<0.001). After 12 months post surgery, further significant improvement was noticed both in women and men (p<0.05 after 6 months and p<0.001 in preoperative assessment). Moreover, 12 month after total hip arthroplasty, average scores obtained in Harris Hip Score were significantly higher in women compared to men (p <0.01), resulting from the fact that more females who had excellent s. Statistical analysis of radiological results of endoprosthesis Proxima stem position obtained in the study group Results of radiological examination, carried out 3 days post surgery, revealed no significant differences between females and males (p> 0.05). In the subsequent postoperative periods, there were no differences between males and females after 1 month (p>0.05) and 3 months post surgery (p>0.05). There was a statistically significant deterioration in the radiological results in women, 6 months after the total hip replacement in comparison to results obtained 3 days after surgery (p<0.05). This deterioration was present also 12 months after surgery. Overall analysis reaveals that at 3 months post surgery, it is possible to notice a significant deterioration of radiological results (p<0.05). The deterioration was more severe 6 months after surgery (p<0.01) and but remained constant at12 months post surgery. Discussion Selection of patients for the total hip joints arthroplasty with endoprosthesis Proxima was based on the clinical and radiological picture, which was confirmed by s obtained using the Harris Hip Score [17]. All patients completed this questionnaire after 3, 6 and 12 post surgery. The obtained results confirmed its functional efficiency, including women diagnosed with developmental dysplasia, in whom excellent and good results with an average of 94 and 86 points had been reported. All variables analyzed by the Harris Hip Score improved significantly, which demonstrates that implant selection, proper surgical techniques, as well as, the rehabilitation care which patients received, were the result of a well-considered and carefully implemented treatment program. Initially, it was presupposed that this type of implant is intended for young people between 40 and 55 years of age. However, in our study, implantation was also done in one 23 years old male and one 62 years old female. The aforementioned male patient was diagnosed with progressive post-traumatic degeneration of the hip joint due to comminuted fracture of the femoral head in the course of an unclear injury. Harris Hip Score questionnaire filled after 12 months of follow-up, gave a result of 85 points, which is considered a good. In radiological evaluation of the endoprosthesis stem seating, performed on the 3rd day post surgery, a good result was reported. However, it was not confirmed in evaluations after 3, 6 and 12 months where it gave unacceptable radiological results. Despite such a radiological picture, the patient did not complain of any pain in the operated limb and the only affected physical activity was the distance walked, which was considerably dependent on the emotional inhibition and a slight limitation of the mobility of operated joint. Implantation of the Proxima in the 62 year old woman was the result of a slow expansion of indications to perform this kind of surgery and the physicians conviction, that essential indications are the biological bone value and the degree of hip joint destruction - not only the patient s age. In assessing the effectiveness of the endoprosthesis Proxima implantation, Pradhan s criteria were used for acetabulum Przegląd Lekarski 2015 / 72 / 7 341

Table XX Radiological s of endoprosthesis stem seating in the study group - females and males in total. Zestawienie zbiorcze wyników radiologicznych osadzenia trzpienia endoprotezy uzyskanych w badanej populacji. Endoprosthesis stem seating radiological result Correct - good Incorrect varus or valgus, without leaning of cone of the endoprosthesis stem against cortical bone of femur acceptable Incorrect varus or valgus, with leaning of cone of the endoprosthesis stem against cortical bone of femur unacceptable seating [18]. For stem seating, we used our own criteria. Obtained results regarding acetabulum seating, prove that it is based on the widely accepted press-fit technique and proper geometry of acetabular cup implantation. They also confirm that this part of the surgical procedure did not cause major problems, even when implantation of the acetabulum required additional stabilization with acetabular screws. However, problems occurred during implantation of the endoprosthesis stem. This part of the surgery was clearly different from methods of implanting stems of other cementless endoprostheses. A different way of the femoral neck cut and, above all, way of preparing the marrow cavity of the proximal stump of the femur, in our opinion caused a malpositioning of the stem. Such a state was observed in 7 patients (11.3%), including 3 men and 4 women. Lack of primary stability of the prosthesis stem, resulted in its further displacement in the direction of varus, which was noticed in subsequent observation periods. Incorrect seating of the endoprosthesis stem in a 12-month observation period i.e. an unacceptable radiological, was reported in 7 patients (11.3%), including 4 men and 3 women. Observation in the following years post surgery, allows us to decipher that proper and stable seating of the endoprosthesis Proxima stem in the bone requires several conditions. In our opinion, it is mainly the adequate width and capacity of femoral neck stump, which correlated, with the volume of the proximal femoral stump. Too narrow a entrance to the marrow cavity, along with big capacity of the proximal femoral stump, results in a lack of primary stabilization of the implant and its varus orientation. or primary seeming stability. It was noticed that in first 3 moths post surgery, in both of these cases, further dislocation of endoprosthesis stem towards Observation period 3 days 1 month 3 months 6 months 12 months number % number % number % number % number % 55 88.7 54 87.1 51 82.3 51 82.3 51 82.3 7 11.3 7 11.3 6 9.3 4 6.4 4 6.4 - - 1 1.6 5 8 7 11.3 7 11.3 Total 62 100 62 100 62 100 62 100 62 100 varus orientation takes place. Good s of endoprosthesis Proxima implantation are also reported by Tomaszewski et al. [12], who observed that Proxima gives better results, when compared to anatomical stem ABG type of prosthesis. According to them, it benefits the quality of life of operated patients. Kim et al. [19] had similar observations with reference to the Proxima endoprosthesis. When it comes to the other short-stem endoprostheses, Floerkrmrier et al. [20], Suksathien et al. [21], and Synder et al. [11] drew attention to the more complicated surgical technique of short-stem type Metha implantation, which is consensual with our own observations as to the Proxima endoprosthesis. Yet it does not change the fact that results of implantation of this kind of endoprostheses to the hip joint are good and they encourage further investigations and analyses. Conclusions 1. Total hip arthroplasty by metaphyseal prosthesis Proxima gives excellent and good functional and radiological results both in a short- and a long-term observation. 2. Efficiency of metaphyseal prosthesis Proxima stem implantation to the marrow cavity of proximal femoral stump expresses itself in primary and secondary stabilization, depends on precise selection for surgery, proper surgical technique and specific anatomical conditions. 3. The most common reasons for primary and secondary dislocation of metaphyseal endoprosthesis Proxima stem towards a varus orientation is incorrect surgical technique, with disregard for importance of specific anatomical conditions of proximal femoral stump to its implantation. Varus dislocation, which is more common than valgus, occurs in the first 3 months from the surgery. References 1. Stodolnik B: Endoproteza cementowa stawu biodrowego typu ORTOMED. Kwart Ortop. 2001; 2: 141-144. 2. Przedborska A, Kopeć J, Smyj K: Ocena wczesnych wyników alloplastyki cementowej, jako metody leczenia zaawansowanej choroby zwyrodnieniowej stawu biodrowego. Kwart Ortop. 2006; 1: 44-54. 3. Golec J, Golec E, Widawski A, Chrzanowski R: Odległe wyniki usprawniania chorych po alloplastyce stawów biodrowych niecementowaną endoprotezą typu ABG. Kwart Ortop. 2002; 3: 163-167. 4. Poznański M, Golec E, Piątkowski M: Wyniki leczenia złamań szyjki kości udowej protezoplastyką połowicza Austin- Moore a. Kwart Ortop. 1998; (Suppl.): 206-211. 5. Magnuszewski JL, Hagner W, Wojtecki B: Odległe wyniki leczenia złamań szyjki kości udowej metodą endoprotezoplastyki połowiczej Austin-Morre a. Kwart Ortop. 2004; 3: 175-177. 6. Decking R, Puhl W, Simon U, Claus LE: Changes In strain distribution of loaded proximal femora caused by different types of cementles femoral stems. Clin Biomech. 2006; 21: 495-501. 7. Widawski A, Golec E, Nowak S: Odlegle wyniki rewizyjnych alloplastyk stawu biodrowego metodą X-change. Chir Narz Ruchu Ortop Pol. 2003; 68: 165-168. 8. Clough TM, Hodgkinson JP: Two stage revision with pseudocapsular resection for recurrent dislocation of total hip prosthesis. J Arthrop. 2000; 15: 1017-1021. 9. Williams JT, Regland PS, Clarke S: Constrained for the ustable hip following total hip arthroplasty: a literature review. Int Ortphop. 2007; 31: 273-277. 10. Milecki M, Kowalczewski J, Wielopolski A, Obrębski M, Okoń T, Marczak D: Modularny, krótki trzpień w endoprotezoplastyce stawu biodrowego doniesienie wstępne. Chir Narz Ruchu Ortop Pol. 2008; 73: 244-247. 11. Synder M, Drobniewski M, Pruszczyński B, Sibilski M: Pierwsze doświadczenia w implantacji trzpienia przynasadowego Metha. Ortop Traumatol Rehabil. 2009; 11: 317-323. 12. Tomaszewski W, Kotela I, Kawik Ł, Bednarenko M, Lorkowski J, Kotela A: Jakość życia pacjentów w ocenie wyników leczenia operacyjnego choroby zwyrodnieniowej stawów biodrowych z wykorzystaniem endoprotezy krótkotrzpieniowej. Ortop Traumatol Rehabil. 2013; 15: 439-457. 13. Golec J, Golec E, Widawski A, Chrzanowski R: Odległe wyniki usprawniania chorych po alloplastyce stawów biodrowych niecementowaną endoprotezą typu ABG. Kwart Ortop. 2002; 3: 163-168. 14. Schmidutz F, Steinbrück A, Wanke-Jellinek L, Pietschmann M, Jansson V, Fottner A: The accuracy of digital templating: a comparision of short-stem total hip arthroplasty and conventional total hip arthroplasty. Inter Orthop. 2012; 36: 1767-1772. 15. Stulberg SD, Dolan M: The short stem: a thinking man s alternative to surface replacement. Prom Hip Repl. 2008; 31: 885-886. 16. Chen HS, Morrey BF, An KN, Luo ZP: Bone remodeling characteristics of a short-stemmed total hip replacement. J Arthrop. 2009; 24: 945-950. 17. Harris R: Clinical results using Müeller-Charnley total hip prosthesis. Clin Orthop. 1972; 86: 95-101. 18. Pradhan R: Plantar anteversion of the acetabular cup as determined from plain anteroposterior radiographs. J Bone Jt Surg. 1999; 81B: 431-435. 19. Kim YH, Choi Y, Kim JS: Comparision of bone mineral density changes around short, metaphysealfitting and conventional cementles anatomical femoral components. J Arthrop. 2011; 26: 931-940. 20. Floerkemeier T, Tscheuschner N, Calliess T, Ezechieli M, Floerkemeier S. et al: Cementles short stem hip arthroplasty METHA as an encouraging option in adults with osteonecrosis. Arch Orthop Trauma Surg. 2012; 132: 1125-1131. 21. Suksathein Y, Narkbunnam R, Sueajui J: Initial clinical and radiographic results with the short stem THA. J Med Assoc Thai 2012; 95 (Suppl.): 26-31. 342 W. Wrażeń et al.