The Association between Acetabulum Fractures and Subsequent Coxarthrosis in a Cohort of 77 Patients-A Retrospective Analysis of Predictors for Secondary Hip Osteoarthritis

OBJECTIVE

the aim of this study was to document the occurrence of THA after acetabulum surgery and examine the factors that predict its occurrence.

METHODS

This study included 77 consecutive patients who were admitted for acetabulum fracture surgery between 2012 and 2019. The inclusion criteria were acetabular fractures and indications for operative management. The exclusion criteria were acetabular fractures treated non-operatively, fractures requiring primary THA, and periprosthetic acetabular fractures. Data concerning demographics, date of injury, date of surgery, surgical approach, stabilization, and further reconstructive surgery were collected retrospectively. The number of patients who underwent THA and their risk factors were recorded. The minimum follow-up for each patient was 2 years of observation. A total of 77 patients with a mean age of 53 years were included.

RESULTS

At a mean follow-up of 2 years, THA was performed in 16 (20.8%) patients due to post-traumatic arthritis. An analysis of the surgical approaches showed that the Kocher-Langenbeck approach increased the risk of THA nearly 12 times compared with the ilioinguinal approach (p = 0.016). Furthermore, the duration of the waiting period for surgery significantly impacted the occurrence of THA, with each additional day leading to an 89% increase in the risk of prosthesis usage (p = 0.001).

CONCLUSIONS

This study suggests that acetabular fractures may lead to post-traumatic hip osteoarthritis. The surgical approach and the waiting time for surgery are potential factors that may predict secondary hip osteoarthritis and the need for subsequent THA. However, further investigations should be performed to establish predictors for secondary hip osteoarthritis, and especially to determine the impact of the surgical approach.

Damage analysis of retrieved BioloxⓇdelta components used in hard and soft bearings

This retrieval study included 43 Biolox delta explants (18 CoC, 25 CoP). Implants were examined macroscopically, whereby damage was evaluated using a semi quantitative scoring system. Confocal microscopy was used to examine wear related damage patterns of the articulating surfaces. Scanning electron microscopy (SEM) with energy-dispersive X-ray spectroscopy (EDS) was used to analyze wear marks on the implant surface and wear debris in periprosthetic tissue samples. Raman spectroscopy and X-ray diffraction (XRD) were used to quantify monoclinic zirconia fractions. On all components, in vivo wear resulted predominantly in different damage patterns caused by metal transfer. In CoC bearings stripe wear was additionally detected, and some implants underwent severe damage due to component breakage. The wear scores were higher for CoC components, with no differences between the scores for CoC heads and liners. Wear features caused comparable roughening on implants from CoC and CoP bearings. SEM studies demonstrated that most wear marks were caused by metal debris released from implant components. Grain pull-out was observed in stripe wear regions. Monoclinic phase shift was observed in a similar quantity on components from CoP and CoC bearings. The increase of monoclinic zirconia content around metal deposits was minimal and was more pronounced in areas of stripe wear. The results of this study indicate, that ZTA components in general undergo minimal wear in both, CoC and CoP bearings, however, it is more pronounced in the former. Metal deposits, as the most common wear feature, have no significant effect on monoclinic phase transition. STATEMENT OF SIGNIFICANCE: In this paper, we classify all damage patterns macroscopically according to an established scoring system and assess them regarding surface roughness (confocal microscopy) and monoclinic phase content (Raman spectroscopy) in order to derive the severity for patients. We compare hard-hard and hard-soft bearings and relate damage patterns with metal transfer based on SEM/EDS examinations. Furthermore, we work out correlations between patient-specific data, cause of revision and the physical condition of each individual sample Our cohort consists of 43 Biolox delta retrievals, a comparatively large quantity. In addition, we address current topics such as metal transfer and, based on the classification of damage patterns, provide incentives and/or meaningful focal points for further research.

Smoking Has No Influence on Outcomes after Repair of the Medial Meniscus in the Hypo and Avascular Zones-A Pilot Study

Complete loss of the meniscus inevitably leads to knee joint degeneration. Smoking is an important factor predicting poor outcome in orthopedics; however, data about its role in meniscus surgery are inconclusive. Smoking could be an important negative factor in isolated meniscus repair. The aim of this paper was to determine the influence of smoking on functional outcomes after isolated all-inside medial meniscus repair. This study included 50 consecutive patients with isolated, traumatic tear of the medial meniscus who underwent knee joint arthroscopy between 2016 and 2019. All-inside arthroscopic repair of the medial meniscus was performed in each case. All patients followed a uniform, postoperative rehabilitation protocol for 8 weeks. The follow-up examination was based on the functional scores at 3 and 6 months postoperatively. According to smoking status there were 17 smokers and 33 non-smokers. The mean number of cigarettes smoked per day was 11, for a mean of 7.4 years, and the mean pack-years index value was 4.9. There was no correlation between smoking years, number of cigarettes smoked per day, pack-years index, and functional outcomes. The arthroscopic inspection of the knee joints revealed cartilage lesions (≤IIº) in eight subjects, suggesting the secondary pathology to the meniscus tear. In this study, we found no evidence of an association between smoking indices and functional outcomes after all-inside repair of chronic medial meniscus tear. The nature of the chronic meniscal tear could be smoking-resistant owing to the poor blood supply to the sites in which these specific lesions occur.

Relationship between long head of the biceps tendon histopathology and long-term functional results in smokers. A time to reevaluate the Bonar score?

Aim

The purpose of this study was to investigate whether there is an association between smoking, the extent of the degeneration process in the biceps tendinopathy, including cells and extracellular matrix (ECM) alterations, and long-term surgical results.

Methods

This study comprised 40 consecutive patients admitted for shoulder arthroscopy due to symptomatic biceps tendinopathy and classified into three groups based on smoking status: active smokers, former smokers, and non-smokers. According to the classical Bonar score criteria, the histopathologic evaluation of the harvested intra-articular portion of the tendon was done. The follow-up examination was based on the American Shoulder and Elbow Surgeons Score (ASES).

Results

A cohort of 32 patients was enrolled in the final follow-up examination; mean 37.56 months. Histopathological evaluation according to the classical Bonar score revealed degeneration of the tendinous tissue in each group but there was no correlation between the extent of degeneration, smoking indexes and the ASES. After revision of Bonar scale within the vascularity criterion, we found a correlation between the extent of degeneration of tendinous tissue, smoking data, ASES score, and the severity of rotator cuff injury.

Conclusion

In this paper, we indicate the ambiguous role of the neovascularization in the biceps tendinopathy, and it was used for modification of the classical Bonar score. Consequently, recalculated, modified Bonar score was correlated positively with smoking indexes and functional outcomes. Furthermore, the morphological alterations of rotator cuff tendons also correlated positively with the extent of biceps tendon degeneration, measured according to the modified scoring system.

The Impact of Smoking on Clinical Results Following the Rotator Cuff and Biceps Tendon Complex Arthroscopic Surgery

The purpose of this study was to investigate the association of smoking and functional outcomes after arthroscopic treatment of complex shoulder injuries: rotator cuff tears (RCTs) with biceps tendon (LHBT) tears. This retrospective case-control study has been conducted on a cohort of patients who underwent shoulder arthroscopy between 2015 and 2017 due to complex injury treatment. The outcomes were assessed using the American Shoulder and Elbow Surgeons Score (ASES), the University of California at Los Angeles (UCLA) Shoulder Score, need for non-steroid anti-inflammatory drugs (NSAIDs) consumption and the visual analog scale (VAS). Complications and changes in smoking status were also noted. A cohort of 59 patients underwent shoulder arthroscopy, due to complex LHBT pathology and RCTs, and were enrolled in the final follow-up examination; with mean duration of 26.03 months. According to smoking status, 27 of patients were classified as smokers, and the remaining 32 were non-smokers. In the examined cohort, 36 patients underwent the LHBT tenotomy and 23 tenodesis. We observed a relationship between smoking status and distribution of various RCTs (p < 0.0001). The mean postoperative ASES and UCLA scores were 80.81 and 30.18 in the smoker's group and 84.06 and 30.93 in the non-smoker's group, respectively. There were no statistically significant differences in pre/postoperative ASES and postoperative UCLA scores between smokers and non-smokers (p > 0.05). The VAS was significantly lower in the non-smokers' group (p = 0.0021). Multi-tendon injuries of the shoulder are a serious challenge for surgeons, and to obtain an excellent functional outcome, we need to limit the negative risk factors, including smoking. Furthermore, there is a significant association between smoking and the occurrence of massive rotator cuff tears, and the pain level measured by the VAS. Simultaneous surgical treatment of RC and LHBT lesions in the smoker population allowed us to obtain the functional outcomes approximated to non-smokers in the long-term follow-up. Of course, we cannot assert that smoking is the real cause of all complications, however, we may assume that this is a very important, negative factor in shoulder arthroscopy.

Biceps Tenodesis versus Tenotomy with Fast Rehabilitation Protocol-A Functional Perspective in Chronic Tendinopathy

The study aimed to evaluate the results after arthroscopic tenodesis and tenotomy of the biceps tendon (LHBT), coupled in tenotomy modality with a personalized postoperative rehabilitation protocol. The study included patients who underwent arthroscopic biceps tenotomy or tenodesis due to chronic biceps tendinopathy. Postoperatively, a standard rehabilitation program was prescribed to the tenodesis group and personalized was introduced in the tenotomy group, respectively. The outcomes were assessed using the American Shoulder and Elbow Surgeons scale (ASES), clinical tests that are dedicated to biceps tendinopathy, the occurrence of a Popeye deformity, night pain, and return to previous sporting activities. A cohort of 67 patients was enrolled in the final follow-up examination (mean 27 months) of which 40 patients underwent tenotomy (60%), and 27 patients (40%) underwent tenodesis. The mean ASES score improved from 48.1 to 87.8 in the tenotomy group and from 44 to 72.7 in the tenodesis group during the follow-up (p < 0.0001). The tenotomy group had better mean postoperative ASES scores than the tenodesis group (p < 0.0001). Positive clinical tests for biceps pathology were noticed more often in patients after LHB tenodesis (p = 0.0541). The Popeye deformity occurred more often in the tenotomy group; however, no patient complained of the visual appearance of the arm contour (p = 0.0128). Moreover, the frequency of night pain decreased in the tenotomy group (p = 0.0059). Return to previous sporting activities was more frequent in the tenotomy group (p = 0.0090). Arthroscopic biceps tenotomy is a reproducible, simple procedure, and augmented by a rapid rehabilitation protocol that provides promising clinical outcomes, reduces shoulder pain, and allows the patient to return to previous sporting activities, even in population older than 50 years.

Current concepts on the morphology of popliteus tendon and its clinical implications

In this review we described the anatomy and biomechanics of popliteus muscle and its tendon. Furthermore, we combined the anatomy with clinics and discussed a wide spectrum of disorders regarding the popliteus and its musculotendinous complex. There are three main anatomical regions of the popliteus musculotendinous complex: the proximal origin, the mid-portion, the distal part on the tibia. The unique localisation and various origins of the tendon, connected with structures such as fibular head, Wrisberg, Humphrey and posterior cruciate ligament, lateral meniscus, medial collateral ligament, give an implication to diagnosis and treatment. Popliteus dysfunction is often overlooked, that is the reason why diagnosis and treatment of its injuries is mostly insufficient. Repetitive or acute direct varus forces, when the tibia is in external rotation, and knee hyperextension or flexion with forced external rotation of the tibia, are the main mechanisms of trauma. Popliteus injuries mainly affect the athletic population and lead to severe activity limitations. Chronic disorders of the popliteus tendon, less known, are often described as tendinopathy and are frequently seen in runners. Their symptoms can mimic the lateral meniscal tears. On the other hand, high-energy traumatic injuries of the popliteus tendon often accompany complex, multi ligamentous injuries seen in competitive sports. We also presented the implication of popliteus tendon in knee arthroplasty, due to its particular exposition to iatrogenic trauma during surgery. The issues such as proper tibial component location and well-designed cut systems are crucial to avoid the popliteus impingement and preserve its structure.

Retrieval analysis of TiN (titanium nitride) coated knee replacements: Coating wear and degradation in vivo

INTRODUCTION

Titanium nitride (TiN) coatings are used in joint arthroplasty to minimize wear and reduce the allergenic potential of metal implants, yet little is known about their performance in knee arthroplasty. This retrieval study examined TiN coated knee replacements to verify in vivo wear and degradation of the coating.

MATERIALS AND METHODS

This study included total and unicompartmental mobile bearing knee replacements retrieved from five patients (eight components) after 13-21 months due to aseptic loosening or infection. Implants were examined using scanning (SEM) and optical microscopy, surface damage was assessed using a semiquantitative scoring system, adhesion was determined using indentation technique testing, surface roughness was measured using contact profilometry.

RESULTS

Although good coating adhesion and no gross failure were observed on all retrievals, coating wear and roughening were evident on tibial bearing surfaces. Multiple microscopic defects (pinholes, craters, titanium droplets) were observed on all samples in SEM studies. Microscopic wear scars indicated that particulate defects significantly contributed to coating wear, acting as third bodies.

CONCLUSION

TiN coatings of knee replacements undergo wear and degradation related to presence of third bodies and microscopic defects on their surface. Since coating integrity may be compromised in vivo, such implants should be used with caution in metal sensitive patients.

The surgical treatment of the long head of biceps tendon and the autotenodesis phenomenon: an ultrasound and arthroscopic study

BACKGROUND

Open or mini-invasive operative procedures are methods of choice in the treatment of the advanced degenerative process of tendinopathy of long head of biceps tendon (LHBT). Cosmetic arm deformity and fatigue are the main complaints after the surgery. Researchers have noticed that in some cases the typical cosmetic deformity is often barely noticeable and the pain is significantly reduced as it occurs after spontaneous LHBT rupture due to extremely advanced tendinopathy.

MATERIALS AND METHODS

This study included 41 of 75 patients who underwent LHBT arthroscopy-assisted tenotomy, followed by examination conducted by means of dedicated clinical tests, the American Shoulder and Elbow Surgeons Score (ASES) and ultrasounds.

RESULTS

The average time interval from surgery to follow-up in the cohort was 31 months, the mean outcome measured with the ASES was 87 points and the "Popeye deformity" complication was present in 15 individuals. In the group of 26 patients where the Popeye deformity was absent and the arm contour was similar to that of the opposite arm, sonographic examination revealed the LHBT stump at the level of the intertubercular groove that was hyperechogenic and wider than the part under the groove.

CONCLUSIONS

Recent reports about the absence of the cosmetic deformity in the anterior area of the arm after shoulder arthroscopy are based on the autotenodesis phenomenon. The intra-articular part of LHBT is painlessly trapped in the bicipital groove by the surrounding soft tissues, which results in unchanged biceps muscle length; however, it is more probable to happen in patients without massive rotator cuff tears.

Breakage of metal hip arthroplasty components: Retrieval and structural analysis

BACKGROUND

Breakage of joint arthroplasty components are rare, yet during an implant retrieval program we found several cases.

OBJECTIVE

In this study we examined the components to determine the causes and mechanisms of breakage of these implants.

METHODS

From our collection of 849 retrievals we selected 682 cases with metal parts (503 hip, 79 knee arthroplasties) and identified fractured components: seven hip resurfacing implants, five total hip replacement stems, one monopolar femoral head, and one modular revision femoral stem from. Implants were examined using optical and scanning electron microscopy; metallographic sections were prepared and samples of periprosthetic tissues underwent microscopic examination.

RESULTS

In the resurfacing components breakage occurred in small stems placed in the femoral neck due to necrosis of femoral heads, with no metal flaws detected. Fatigue breakage of femoral stems was caused by presence of material flaws in the CoCrMo alloy, and corrosion. The monopolar head failed in fatigue fracture mechanism, breakage was initiated in an undercut near the taper connection for femoral component. The modular stem from Ti alloy sustained fatigue fracture induced by corrosion caused by debris from previously revised stem; no material flaws were detected in this sample. In most cases periprosthetic tissues had a morphology typical for aseptic loosening.

CONCLUSIONS

In our series failure was caused by material flaws, presence of stress raisers and localized corrosion. Our findings indicate that sharp edges and other features which can act as stress raisers should be avoided in newly designed implants. Corrosion induced fracture of the modular Ti stem indicates the need for a detailed debridement of periprosthetic tissues during revision arthroplasties.

Bicompartmental locked bucket-handle tears of menisci concealing the concomitant anterior cruciate ligament injury for 2 years - a case report

Locked bucket-handle tears of both medial and lateral menisci, called in literature "Jack and Jill lesion", with simultaneous anterior cruciate ligament (ACL) injury is an extremely unusual phenomenon. It was reported only in a few cases in literature, which were unfortunately highly differentiated in the field of trauma mechanism, treatment options and postoperative care. Authors presented a clinical case of patient with a locked knee joint, by the torn both menisci, what masked the simultaneous ACL rupture and supremely imitated a stable joint. The locked knee is a clinical case demanding the urgent intervention to prevent further damages to the joint structures. Surprisingly, the patient after locking of the menisci and migration of their inner fragments to the intercondylar notch, started to feel the affected joint stabile and dismissed from the further treatment for next 2 years. Complex trauma needs a complex treatment, and a single-stage or multi-stage surgical approach is performed. Authors chose a two-steps surgical procedure with primary meniscal repair and secondary, early ACL reconstruction.  

Osseointegration of hydroxyapatite coatings doped with silver nanoparticles: scanning electron microscopy studies on a rabbit model

BACKGROUND

Modern joint arthroplasties rely on osseointegration of metal components through bone ingrowth into hydroxyapatite (HA) layers. However, such surfaces are prone to colonisation by bacteria and formation of biofilms. Application of silver nanoparticles (SNs) to hydroxyapatite coatings could reduce the risk of infection; however, little is known about how this would affect the process of bone ingrowth. This study examined osseointegration of conventional and SN doped HA coatings in a rabbit model.

MATERIALS AND METHODS

In this study, 12 cylindrical implants coated with conven- tional and SN doped HA were implanted into New Zealand white rabbit femora, with each animal receiving both types of implants. After 12 weeks, rabbits were sacrificed, their femora were harvested and implants removed during pull-out testing. Retrieved samples were dehydrated, sputter coated and observed using a scanning electron microscope (SEM) to verify bony ingrowth and retention of SNs.

RESULTS

The percentage of implant in direct contact with bone was measured in cross-sections of implants. The SEM analysis demonstrated that osseointegration of the SN doped coatings was similar to the conventional HA samples. A similar morphology of newly formed trabecular bone was observed in both implants, with silver doped HA-coated implants retaining multiple nanoparticles in areas which were not overgrown by bone. Analysis of the bone-implant contact area revealed comparable results for both types of coatings. These finding indicated that SN doped HA coatings are characterised by good osseointegrative properties.

CONCLUSIONS

Since SNs were found in areas not covered by mineralised bone, it is assumed that the antimicrobial properties of the modified coating may be retained for 12 weeks after implantation. Additional studies are required to fine--tune the composition of HA coatings with SNs, to ensure optimal osseointegrative and antimicrobial properties.

Reactions of bone, liver and kidney tissues to orthopaedic implants with silver nanoparticle doped hydroxyapatite coatings: microscopic examination in a rabbit model

Background: Periprosthetic joint infections are severe complications of arthroplasty, difficult to manage due to biofilm formation on the components. Recently, the use of silver nanoparticles (SNs) has emerged as a method of preventing biofilm formation on orthopaedic implants, however little is known about the systematic toxicity of SNs.Aim: This study used a rabbit model to examine the tissue response of bone, liver and kidney to prototype components with SN doped hydroxyapatite (HA) coatings.Materials and methods: Twelve prototype implants (six with HA, six with SN doped HA coatings) were implanted into the femora of twelve New Zealand Rabbits. After 6 weeks, the animals were euthanised, their femora and samples of livers and kidneys harvested to prepare microscopic slides. The slides were examined for the presence inflammatory or toxic reactions to SNs, implants were examined using scanning electron microscopy (SEM) to determine structural changes related to implantation and verify retention of SNs in vivo.Results: SEM demonstrated that SNs formed submicron conglomerates, which were retained after 6 weeks in vivo and did not interfere with osseointegration. Histologic studies of bone fragments demonstrated no signs of acute toxicity and inflammation. No inflammatory reaction was observed in kidneys, although in some samples signs of acute renal failure related to euthanasia were found. No severe toxic reaction was found in liver samples, however fatty degeneration of liver was found in some animals.Conclusions: This study documented good osteointegration of implants with SN doped HA coatings with low systematic toxicity of SNs.

Sonography in the instability of the long head of the biceps tendon confronted with histopathologic and arthroscopic findings

BACKGROUND

Disorders of the long head of the biceps (LHB) tendon are a common source of shoulder pain and disability. This tendon can be well visualised using ultrasonography; however, little is known if such examination allows clinicians to predict pathological changes of the tendon structure. In the study described below, we compare preoperative sonographic findings with the data from shoulder arthroscopy and microscopic examination of the excised tendon fragments in 19 consecutive patients with LHB tendinopathy and clinical suspicion of its instability.

MATERIALS AND METHODS

Preoperative ultrasonographic (US) inspection assessed several features of the tendon, whereas its stability was verified arthroscopically. In all cases, tenodesis or tenotomy procedures were performed and excised tendon fragments were harvested for microscopic examination based on the semiquantitative Bonar score.

RESULTS

The most common US findings were hypoechoic areas, tendon thickening, an increased power Doppler signal and mechanical instability. Just as shoulder arthroscopy confirmed all mechanical instability cases detected in US, microscopic assessment revealed advanced degeneration in all samples.

CONCLUSIONS

Our study indicates that US is a useful tool in identifying cases of advanced instability and LHB tendinopathy, whereas biceps tendon instability is a biomechanically complex, gradually progressing phenomenon, frequently associated with additional shoulder lesions.

Tendon - function-related structure, simple healing process and mysterious ageing

Tendons are connective tissue structures of paramount importance to human ability of locomotion. The understanding of their physiology and pathology is gaining importance as advances in regenerative medicine are being made today. So far, very few studies were conducted to extend the knowledge about pathology, healing response and management of tendon lesions. In this paper we summarise actual knowledge on structure, process of healing and ageing of the tendons. The structure of tendon is optimised for the best performance of the tissue. Despite the simplicity of the healing response, numerous studies showed that the problems with full recovery are common and much more significant than we thought; that is why we discussed the issue of immobilisation and mechanical stimulation during healing process. The phenomenon of tendons' ageing is poorly understood. Although it seems to be a natural and painless process, it is completely different from degeneration in tendinopathy. Recent studies of biological treatment reported faster and optimal healing of the tendons when augmented by growth factors and stem cells. Despite advances in biology of tendons, management of their injuries is still a challenge for physicians; therefore, further studies are required to improve treatment outcomes.

Process of neovascularisation compared with pain intensity in tendinopathy of the long head of the biceps brachii tendon associated with concomitant shoulder disorders, after arthroscopic treatment. Microscopic evaluation supported by immunohistochemical

BACKGROUND

Tendinopathy of the long head of the biceps brachii tendon (LHBT) is one of the most common, painful conditions of the anterior part of the shoulder and often coexists with rotator cuff tears. Multifactorial aetiopathology of tendi-nopathy is poorly understood; however, several studies indicated that it is seen predominantly in areas with decreased vascularity of the tissue; the pathology is also characterised by expansive and abundant neovascular in-growth. The aim of the study was to investigate the relationship between the neovascularisation of proximal part of the LHBT and pain along the bicipital groove.

MATERIALS AND METHODS

Tissue material was obtained from 28 patients who underwent a shoulder arthroscopy and experienced pain along the bicipital groove measured using Visual-Analog Scale (VAS) score. CD31 and CD34 molecules were visualised by immunohistochemical method to assess biceps tendon neovascula-risation and quantify it based on a Bonar scoring system.

RESULTS

Although all patients reported pain prior to arthroscopy (mean VAS score was 7.5), microscopic examination did not reveal neovascularisation in all cases. Immunohistochemical staining for CD31 and CD34 allowed for very precise visualisation and quantification of neovascularisation; however there was also no correlation between vessels in-growth scores and pain.

CONCLUSIONS

The obtained data suggest that neovascularisation process in tendino-pathy is not directly related to pain; however, further studies are needed to explain its significance in the LHBT tendinopathy. (Folia Morphol 2018; 77, 2: 378-385).

Peripheral snap-fit locking mechanisms and smooth surface finish of tibial trays reduce backside wear in fixed-bearing total knee arthroplasty

Background and purpose - Severe backside wear, observed in older generations of total knee replacements (TKRs), led to redesign of locking mechanisms to reduce micromotions between tibial tray and inlay. Since little is known about whether this effectively reduces backside wear in modern designs, we examined backside damage in retrievals of various contemporary fixed-bearing TKRs. Patients and methods - A consecutive series of 102 inlays with a peripheral (Stryker Triathlon, Stryker Scorpio, DePuy PFC Sigma, Aesculap Search Evolution) or dovetail locking mechanism (Zimmer NexGen, Smith and Nephew Genesis II) was examined. Articular and backside surface damage was evaluated using the semiquantitative Hood scale. Inlays were examined using scanning electron microscopy (SEM) to determine backside wear mechanisms. Results - Mean Hood scores for articular (A) and backside (B) surfaces were similar in most implants-Triathlon (A: 46, B: 22), Genesis II (A: 55, B: 24), Scorpio (A: 57, B: 24), PFC (A: 52, B: 20); Search (A: 56, B: 24)-except the NexGen knee (A: 57, B: 60), which had statistically significantly higher backside wear scores. SEM studies showed backside damage caused by abrasion related to micromotion in designs with dovetail locking mechanisms, especially in the unpolished NexGen trays. In implants with peripheral liner locking mechanism, there were no signs of micromotion or abrasion. Instead, "tray transfer" of polyethylene and flattening of machining was observed. Interpretation - Although this retrieval study may not represent well-functioning TKRs, we found that a smooth surface finish and a peripheral locking mechanism reduce backside wear in vivo, but further studies are required to determine whether this actually leads to reduced osteolysis and lower failure rates.

Remodeling of bone tissue around the distal part of Zweymüller stem

BACKGROUND

The Zweymüller stem is well-known in Europe and widely used for total hip replacement since 1980. Few authors have noted the presence of increased bone density below the tip of the stem; however, the underlying mechanism is still unknown. The aim of this study was to reveal factors influencing bone remodeling around the tip of the Zweymüller stem.

MATERIAL AND METHODS

102 consecutive patients (69 women and 33 men) who received a second generation Zweymüller type stem (123 prostheses) were included. Mean follow-up was 9.2 years (6 - 15 years). A Cortical Index (CI) was defined as the ratio between stem width and external cortical diameter in Gruen zones 3 and 5.

RESULTS

Patients with a wide femoral canal and thin cortical bone (CI ≥0.4) demonstrated a positive correlation with the presence of increased bone density (IBD) below the stem (p<0.0001, r=0.6028). During follow-up, the mean Cortical Index decreased by 0.02 points and mean thickness of cortical bone in zone 3 and 5 increased by 2.0 millimeters. Cortical thickening was more pronounced in cases without IBD (1.5 vs. 2.4 mm, p=0.0172).

CONCLUSIONS

1. Thin cortical layers and a wide femoral canal (CI ≥0.4) can result in the presence of IBD below the stem. 2. IBDs probably appear due to mechanical stress transferred by the tip of stem to cancellous bone in Gruen zone 4. 3. Based on clinical symptoms, we conclude that the presence of IBD is not associated with increased aseptic loosening or stem instability.

Pigmented Villonodular Synovitis - Various Manifestations, Inconsistent Terminology and Treatment. Cases Study

Pigmented villonodular synovitis (PVNS) as well as tenosynovial giant cell tumor (TGCT) are both diagnosed and described in two forms, namely a localized and diffuse type. They form a diverse group of proliferative lesions in articular synovium and tendon sheaths. The inconsistent terminology impedes communication between patients, orthopedic surgeons, radiologists and pathologists, leading to misunderstandings and delaying treatment. In this paper, we present three cases of PVNS/TGCT (involving the fourth toe extensor tendon sheath, hip joint after resurfacing and flexor hallucis longus tendon sheath) together with suggestions regarding the unification of the terminology as well as diagnosis and treatment.

Knee Function and Subjective Stability Following Total Condylar Arthroplasty in Joints with Preoperative Varus or Valgus Deformity

BACKGROUND

Total knee arthroplasty in joints with valgus or varus deformity is technically demanding. Careful soft tissue balance as well as restitution of anatomical knee axis has a profound effect on postoperative function of the joint, however little is known about differences in subjective stability following surgery between preoperative valgus and varus knees.

MATERIAL AND METHODS

Studied group consisted of 60 patients who underwent total condylar knee arthroplasty with one type of implant (Stryker Triathlon). Mean follow-up was 2,9 years (1-6 years). The group included 25 patients with valgus and 35 patients with varus preoperative deformity. All patients filled Knee Injury and Osteoarthritis Outcome Score (KOOS) forms. Detailed clinical and radiological assessment was performed.

RESULTS

Mean KOOS score was slightly higher in patients with varus deformity, as compared to cases with valgus deformity. At physical examination higher LCL deficiency rate was observed in varus knees. Subjective instability was reported by eight patients (5 valgus and 3 varus). In all cases instability coexisted with decreased MCL tightness and implant position was correct in those patients. No subjective instability was reported by patients with clinical LCL deficiency. Furthermore KOOS scores in these patients were higher (85,8) as compared to cases with decreased MCL tension (79,1).

CONCLUSIONS

1. In patients with proper implant alignment subjective instability is related to postoperative MCL deficiency, regardless preoperative deformity in coronal plane. 2. The post-op LCL laxity does not compromise subjective stability, nor influence subjective outcome, as demonstrated with KOOS scores.

30-year survival of a McKee-Farrar hip prosthesis--case report and microscopic analysis of bearing surface

We report a case of a female patient using a McKee-Farrar prosthesis for 30 years, until revision surgery for aseptic loosening. Electron microscopy analysis of bearing surface of the retrieved implant was performed, and the results were presented in comparison with previously published papers.

[Porous tantalum modular cups in revision hip arthroplasty]

INTRODUCTION

Modem indications for use of cemented or uncemented implants in revision hip arthroplasty are comparable. The use of bone cement provides predictable short term results, but the lack of osteointegration deteriorates its long term durability. Uncemented implants undergo osteointegration, but reduced contact with host bone may cause early loosening. Modular porous tantalum implants are highly osteointegrative, and the availability of bone stock augments increases the versatility of this system.

MATERIAL AND METHODS

The study group consisted of 20 patients (21 hips) who underwent a revision hip arthroplasty using Trabecular Metal acetabular revision system. The follow-up period was between 7 and 31 months (average 20 months). All patients were evaluated with HHS and conventional radiography.

RESULTS

The mean HHS increased form40.45 (range 18.74-56.65) preoperatively to 78.8 (56.5-96) at the last follow-up. No mechanical failures, nor septic complications were noted.

[Total knee replacement in joints with severe varus and bone deficiency]

INTRODUCTION

Total knee replacement in knees with severe valgus and defects of the medial tibial condyle are at higher risk complications than in knees with a correct axial allignement.

MATERIAL AND METHODS

The study group included 10 patients (11 knees) with with severe valgus and defects of the medial tibial condyle in which TKR was performed. In 8 cases bone defects were filled with bone autograft in 3 cases defects were filled with metal augments. The mean follow-up was 37 months (26 months to 4 years). Clinical results were measured with the knee society score, the level of activity was evaluated with the UCLA score. Radiographic evaluation was based on radiograms taken preoperatively, postoperatively and at the follow-up examination.

RESULTS

In All cases an improvement in clinical results was noted, the mean KSS result rised from 25.3 preoperatively to 87 postoperatively and the level of activity rised from 3.4 to 5.4 postoperatively. No signs of loosening were found in radiographic evaluation.

CONCLUSIONS

TKR in joint with severe varus and medial tibial condyle defects creates a need for the reconstruction of defects. In lesser defects reconstruction with bone autografts is sufficient, in severe cases filling the defect with metal augments is needed. When indicitions are followed both methods provide good clinical results.

[Reactions of bone tissue around the ABG II stem]

The uncemented total hip replacement became a standard in treatment of the severe hip osteoarthritis. Its long term efficiency is based on the correct osteointegration which depends on the adequate implantation. Material. The study group consisted of 49 patients (52 hips) following total hip replacement with ABG II stem and Trident PSL cup. The follow-up ranged between 6 months and 2 years.

METHODS

In each case the Harris hip score was performed and high resolution x-rays were taken. On X-ray the fit and position of the stem, linear osteolysis around the stem and bone atrophy at the greater trochanter were evaluated. Results. The mean HHS at the last follow up was 90.4 (50-99). The mean angle of the stem position was 2.9 varus. The mean fit index was was 0.75. The significant correlation was found between the fit index and the varus stem position angle. The linear osteolysis surrounding the stemin the 1st Gruen zone was found in 70% of cases. The phenomenon of the linear radiolucenecy surrounded by linear densification was found in the 76% of cases. Bone atrophy at the greater trochanter was found in the 42% of cases. Conclusions. The use of ABG II stems provided very good clinical results. The stem has a tendency to a varus position, which seems to be connected with the use of the too small stems. Specific radiographic observations create a need of futher follow-up, but existed without the influence on the clinical results.

[Current views on the pathogenesis of osteoarthritis]

Degenerative joint disease is the most common joint pathology and the main cause of disability of elderly people in developed countries. It is caused by imbalance between degeneration and regeneration of articular cartilage accompanied by pathological changes of other joint structures. No generally recognizable description of the pathogenetic pathway of osteoarthritis (OA) exists so far, however recent studies have widened the knowledge of the underlying pathology. In this review views regarding the role of genetic and mechanical factors in OA pathogenesis were presented. The role of pro-inflammatory mediators such as cytokines (IL-1, TNF-alfa, IL-6), lipid mediators, NO, reactive oxygen species, were discussed. The contribution of adipokines (fat tissue derived hormones with cytokine activity) to the pathogenesis of degenerative joint disease was also described. The role of synovial membrane, articular cartilage, subchondral bone and such structures as osteophytes and infrapatellar fat pad in development of osteoarthritis were presented as well.

[Physical activity and quality of life following total uncemented hip replacement and hip resurfacing]

INTRODUCTION

The influence of physical activity on the survival of total hip replacement remains not fully recognized. It is unclear which activities are beneficient for patients following THR.

MATERIAL

The study was conducted on group of 87 patients (94 hips) following uncemented THR with ABGII/Trident and 45 patients (51 hips) following hip resurfacing. The follow-up period was 6-30 months for THR group and 6-42 months for resurfacing group.

METHODS

The patients answered a questionnaire based on WOMAC and SF-36 score, UCLA activity scale with additional questions concerning patients physical activity, working and place of living.

RESULTS

In WOMAC, physical domains of SF-36 and UCLA activity score patients following hip resurfacing showed better results. The most preferred activity in both groups was exercise walking and biking. The last one was particularly preferred by patients living in rural areas.

CONCLUSION

The vast majority of patients restricted their activity to disciplines with a safe range of hip weight bearing.

[Pedobarographic evaluation of the foot after Keller's procedure for Hallux valgus and Hallux rigidus]

Hallux valgus and hallux rigidus are common foot deformities. One of possible procedures is Keller's surgery. The purpose of this study is to evaluate the use of pedobarography for postoperative evaluation of the foot. Group. We examined 54 patients aged 48 to 82 (average 60.4) after surgical treatment of Hallux valgus (78 feet) or Hallux Rigidus (15 feet). Methods. Retrospective pedobarographic evaluation 1 to 11 years after surgery was performed using PEL-38 system. Clinical results. All patients had markedly increased pressure under the 2nd and 3rd metatarsal heads comparing to other forefoot regions. Only 17% of feet had distal dynamic transverse arch during stance phase of gait. There was severe impairment of function of the great toe in entire group. In 82.7% of feet there was no ground contact of the great toe in dynamic evaluation of the stance phase. Conclusion. Pedobarographic examination has good value in postoperative functional assessment of the foot. It's a valuable addition to physical and radiological examination.