Implant-specific Complications Research Articles

Custom designed and 3D-printed titanium pelvic implants for acetabular reconstruction after tumour resection.

Reconstructive procedure following resection of large pelvic tumours around the hip joint remains a complex challenge. This study presents a retrospective case series of patients presenting with benign or malignant pelvic tumour for which an internal hemipelvectomy including the hip joint and subsequent reconstruction with a custom designed 3-dimensional printed titanium pelvic implant (3DPPI) has been performed between August 2013 and January 2018. 15 consecutive patients with a median age of 33.9 years (IQR 26.4-72.2) and a median BMI of 20.7 kg/m2 (IQR 19.0-33.3) were reviewed after median follow-up of 33.8 months (IQR 24.0-78.1). The majority of patients presented with a malignant tumour as their principal diagnosis (n = 13, 86.7%). The median surgical time was 5.5 hours (IQR 4.5-8.5) and median peri-operative blood loss was 5000 ml (IQR 2000-10000). The median MSTS score at follow-up was 63.3% (IQR 51.7-86.7%). The median NRS in rest was 0.0 (IQR 0.0-5.0), the median NRS during activity was 2.0 (IQR 0.5-7.0) and the median HOOS-PS was 76.6% (IQR 67.9-91.0). 4 patients had implant-specific complications (n = 4, 26.6%); 1 hip dislocation (Henderson type 1a), 3 structural complications (type 3a), 1 deep infection (type 4a) and 1 local tumour recurrence (type 5b). At follow-up, 4 out of 15 implants were classified as a failure, resulting in an implant survival rate of 73.3%. Acceptable peri-operative outcomes, functional results, complication rates and short-term implant survival can be achieved in a cohort of complex patients undergoing 3DPPI reconstruction after hemipelvectomy including the acetabulum.

The use of suture anchors in posterolateral corner reconstruction in the setting of multiligament knee injury: Clinical and radiological outcomes in 58 patients with a mean follow-up of 15 months

The two-tailed posterolateral corner (PLC) reconstruction in multi-ligament knee injuries (MLKI) is mostly described with interference screws. Data on the use of suture anchors is limited. Our purpose was to report clinical and radiological outcomes of the modified technique, and to describe a technique for concomitant biceps femoris tendon repair. Demographic data, clinical and radiological outcomes were collected from 60 patients who underwent two-tailed PLC reconstruction in the setting of MLKI between 2017 and 2021. Patients were assessed for range of motion (ROM) and functional outcomes including Tegner, Lysholm and International Knee Documentation Committee (IKDC) scores. Complications and reoperations were also reported. Radiographic parameters focused on measurements of the lateral femorotibial space in varus stress views to evaluate stability and determine failure rate. Analysis based on time from injury to reconstruction was additionally performed. With two (3.3%) loss to follow-up, 58 patients with a mean age of 33.8 and a mean follow-up of 15.1 months (range: 4.2–44.8) were included. Sixty-five percent were men. Knee dislocation grades included KD 3-L, 4 and 5. No isolated PLC reconstructions were performed. Twenty-five patients (43.1%) underwent acute reconstruction and 5 (8.6%) presented with a neurovascular injury. Seventy-five percent had concomitant meniscal tears requiring repair. The mean postoperative ROM was 1.7–133.2 degrees. Mean Tegner, Lysholm, and IKDC scores were 5.1 ± 2.3, 84.6 ± 12.1, and 73.4 ± 18.2, respectively. The mean lateral femorotibial space on varus stress views was 0.3 ± 1.2 mm. Fourteen (24.1%) patients required revision surgery for hardware removal, stiffness, or clinical failure, and 6 (10.3%) had complications including infection and anchor pull-out. In addition, patients with acute reconstructions had better functional outcomes compared to those who presented with a chronic injury. The use of suture anchors as fixation method of choice for fibular head docking in two-tailed PLC reconstruction can reliably restore varus stability and provide fair functional outcomes in patients with either acute or chronic MLKI with posterolateral instability, associated with a low rate of implant-specific complications.

Clinical and radiological outcome of all-suture anchors in shoulder and elbow surgery.

All-suture anchors (ASAs) are noted to cause various bone reactions when used in upper limb surgery but clinical implications are unknown. 88 shoulders and 151 elbows with a mean follow-up of 47.1 ± 17.7 months were invited for follow-up including clinical examination, questionnaires and radiographs. The anchor drill holes were radiographically assessed. At final follow up, mean DASH was 12.9 ± 13.8 and mean VAS 2.2 ± 2.4 in the shoulder population. In the elbow group mean MEPS was 91.8 ± 12.7 and mean VAS 1.5 ± 1.9. Implant-specific complications were seen in 10 elbow cases but none in the shoulder group. The mean diameter of the 1.4 mm all-suture anchor drill hole was enlarged to 2.5 ± 1.4 mm in the shoulder group and to 2.9 ± 1.0 mm in the elbow group. 50% of the 1.4 mm anchor drill holes showed abnormal morphology but these morphologic changes did not correlate with clinical outcome, complications or reoperation rate. Satisfying clinical outcomes are found in upper limb surgery using ASAs. Various bone changes are seen after implantation of an ASA, but these are not clinically relevant. Long-term consecutive follow-up data is required.

Dual Mobility in Total Hip Arthroplasty: Biomechanics, Indications and Complications-Current Concepts.

Dual-mobility (DM) articulations are increasingly utilized to prevent or manage hip instability after total hip arthroplasty (THA). DM cups offer enhanced stability due to the dual articulation resulting in larger jump distance and greater range of motion before impingement. Improvement in design features and biomaterials has contributed to increased interest in dual-mobility articulations due to lower risk of complications compared to their historic rates. The incidence of implant-specific complications like intra-prosthetic dislocation (IPD) and wear has reduced with newer-generation implants. DM THAs are used in primary THA in patients with high risk for dislocation, e.g. neuromuscular disorder, femoral neck fracture, spinopelvic deformity, etc. They offer an attractive alternative option to constrained liner for treatment of hip instability in revision THA. The medium- to short-term results with DM THA have been encouraging in primary and revision THA. However, there are concerns of fretting, corrosion and long-term survivorship with DM THA. Hence, longer-term studies and surveillance are required for the safe use of DM THA in clinical practice.

Intramedullary nailing as a safe and efficient treatment option for all types of displaced proximal humeral fractures in geriatric patients: A retrospective evaluation of 49 patients treated with the new Targon PH+ nail.

Implant specific complications and outcome for the use of proximal humeral nails in different fracture types are not well described. Evaluation of adverse effects and outcome of patients treated with the new Targon PH+ implant for proximal humeral fractures in a geriatric population. A consecutive series of patients from a single institution was retrospectively evaluated. Adverse events (AE) were assessed from patients' files and during follow-up examination. Current pain level was evaluated using the Visual Analogue Scale (VAS). The disability score of arm, shoulder and hand (DASH) as well as the Constant-Murley score were assessed. Patient satisfaction was evaluated by questionnaire. Forty-nine patients with a mean age of 72.0 ± 10.0 years were included with a follow-up of 2.2 years. Five patients showed twopart fractures (10%), 24 threepart fractures (50%) and 20 fourpart fractures (40%). Additional shaft fracture occurred in twelve cases (24%). Implant-related AE were recorded in six cases (12%). Pain under strain was moderate with a mean of 27.6 ± 27.1 mm. DASH score showed a mean of 25.9 ± 24.9. Constant score of the affected shoulder was 57 ± 23.8 with a mean difference of 16 points compared to reference shoulder. No significant differences in AE, VAS, DASH or Constant score could be found according to fracture groups. Most patients were satisfied with the surgical outcome (84%). The Targon PH+ nail demonstrated good functional results and low adverse events in geriatric patients. Additional studies including less experienced centres are required to further evaluate the possible benefits of this implant.

Conversion of cemented revision total knee prostheses to arthrodesis using custom-made arthrodesis modules that preserve the cemented stem anchorage in patients with long-established extensor mechanism insufficiency: A case series

IntroductionLong-established extensor mechanism insufficiency that defies reconstruction is a rare, but devastating, complication after revision total knee arthroplasty (RTKA) that may require arthrodesis. For cemented stem guided knee prostheses with firmly attached stems, prosthesis explantation can lead to significant bone stock loss that may, at worst, make knee arthrodesis significantly more difficult or impossible to achieve. Under these circumstances, conversion of the cemented knee prosthesis with custom-made arthrodesis modules that preserve the existing stem anchorage may be a low-risk alternative. This case series presents this type of conversion to arthrodesis, which was performed for patients with a non-reconstructable, long-established extensor mechanism insufficiency. MethodsAfter intraoperatively ascertaining that reconstruction of the extensor mechanism insufficiency was impossible, the inlying revision prosthesis was converted into arthrodesis with custom-made arthrodesis modules, without explanting the cemented stems. ResultsConversion to arthrodesis was performed in four patients. There was no histopathological or microbiological evidence of a periprosthetic joint infection. Clinical follow-up showed a low level of pain, with a stable knee joint and proper implant position. The Oxford Knee Score increased from 20.5 (95% CI 17–26) to 35.5 (95% CI 30–36) points. The visual analog scale decreased from 5.5 (95% CI 4–7) pre-operatively to 1.5 (95% CI 1–2) points at last follow-up. No implant-specific complications occurred. ConclusionsConversion of cemented RTKA with firmly attached cemented stems, without evidence of loosening, to arthrodesis might be a surgical treatment strategy for patients with a long-established extensor mechanism insufficiency that cannot be reconstructed.

A case series of cementless revision total knee arthroplasty in patients with benzoyl peroxide allergy.

The contact allergens nickel, cobalt, and chromium are often discussed as possible triggers of allergic reactions to orthopedic implants. Additionally, acrylates and polymerization additives in bone cement (e.g., benzoyl peroxide (BPO)) have been implicated as triggers of eczema, wound healing disorders, and aseptic implant loosening. We report about six patients with aseptic loosening after total knee arthroplasty (TKA), who underwent revision surgery after testing positive for BPO hypersensitivity. After clarification of possible other causes of implant failure, epicutaneous testing had been performed and the implants were replaced in a two-stage procedure with cementless, diaphyseal anchoring, hypoallergenic (TiNb-coated) revision endoprostheses. Epicutaneous testing revealed a BPO allergy in all six patients and an additional nickel allergy in three of the six patients. There was no histopathological or microbiological evidence for a periprosthetic infection. The clinical follow-up showed a low level of pain with good function, a stable knee joint, and proper implant position. The Knee Society Score (KSS) with its subscales Knee Score and Functional Score improved post-operatively from 43 to 70 points and from 47.5 to 68.3 points, respectively. Two implant-specific complications occurred: femoral stress shielding two years post-operatively with no further need for action and aseptic loosening of the tibial stem with the need of revision threeyears post-operatively. The regression of complaints after replacement with cementless and nickel-free revision implants suggests allergic implant intolerance. Implantation of a cementless, hypoallergenic endoprosthesis might, therefore, be a surgical treatment strategy in patients with evidence of allergies.

Effective patellofemoral joint stabilization and low complication rates using a hardware-free MPFL reconstruction technique with an intra-operative adjustment of the graft tension.

Even if medial patellofemoral ligament (MPFL) reconstruction is a proven method, complications such as implant loosening, patella fractures, recurrent luxations, knee pain or knee stiffness are frequently described. Besides a correct tunnel positioning and implant-specific complications, this might be caused by difficulties with an appropriate graft tensioning. The study presented here is a necessary first step in exploring our technique of a double-limbed, hardware-free MPFL reconstruction, which provides another way to test and adjust the graft tension before permanent fastening. Thirty consecutive patients (m/f=18/12) with recurrent dislocations were evaluated after a mean follow-up of 24months. Patients who had additional procedures such as a trochleoplasties, tibial tubercle transfers and derotational osteotomies were not included. Besides a standardized clinical examination, different scorings and possible complications were evaluated. The mean Kujala score improved significantly from 57±15 to 92±10. The Lysholm and IKDC score increased significantly from 59±11 to 95±6 and from 49±9 to 89±9, respectively. No patient reported a re-dislocation, subluxation or showed a positive apprehension. A total of 23 patients were engaged in regular physical activities. All but one, who lost interest, returned to the same sports. Because some did not follow our recommendation to return to sports after a rehab of at least 10-12weeks, the period for a return was relatively short (median of 12weeks, range 3-25weeks). Four patients reported a moderate anterior knee pain only occurring after increased loads such as longer runs or workouts. One of these showed a slight flexion deficit of less than 20°. A severe motion deficit or stiffness was not noticed. Even if a larger, clinical outcome study is needed to ensure the efficacy and safety of our method, it seems to provide a good clinical outcome, a correspondingly high satisfaction and a low incidence of complications. The possibility to adjust graft tension might help in minimizing complications caused by difficulties with an appropriate graft tension. IV.

Rare implant-specific complications of the MoPyC radial head prosthesis

According to currently available data, the clinical short-term results of the MoPyC radial head prosthesis (Bioprofile, Tornier, Montbonnot-Saint-Martin, France) seem favorable. However, we have encountered several implant-specific complications in recent years. Hence, this case series reports rare complications after radial head arthroplasty with the MoPyC prosthesis to make surgeons aware of their existence and to provide information about the underlying cause and possible salvage strategies. A retrospective chart review from 2011 to 2016 was conducted to identify all adult patients with a minimum 2-year follow-up who underwent or were referred after radial head arthroplasty with the MoPyC radial head prosthesis and experienced implant-related complications. Five patients with 7 implant-related complications were found. One patient experienced breakage of the pyrocarbon head. In another patient, breakage of the stem and-after revision surgery-partial breakage were observed. Disassembly of the prosthesis was seen in 1 case. Extensive periprosthetic stress shielding was seen in 3 patients resulting in symptomatic loosening (1), periprosthetic radial neck fracture (1), and stem migration (1). Whereas clinical short-term results of the MoPyC radial head prosthesis are satisfactory, rare implant-related complications can occur. Surgeons should be aware of these complications as they may lead to a poor outcome.

Operative Versorgung von Azetabulumfrakturen mit der neuen Azetabulumflügelplatte

Introduction: There have been significant increases in the number of acetabular fractures in elderly patients with primarily ventral pathology and medial protrusion of the femoral head. We have developed the "acetabulum wing plate", which is designed to facilitate repositioning, with its anatomically precontoured structure, and which offers full support of the quadrilateral surface, thus counteracting the force of the femoral head pushing inwards. Conventional plate osteosynthesis only provides insufficient support to the medial surface. After a successful series of biomechanical tests, we now report a clinical case series. Material and Methods: Between April 2012 and August 2013, a total of twelve patients underwent plate osteosynthesis using the precontoured plate described above. The patients (ten male, two female) were aged between 45 and 87 years, the average age being 62.5 years. We were able to perform all osteosynthesis with the modified Stoppa approach, in combination with the first window of the ilioinguinal approach (according to Letournel). In most patients, the plate was applied without complications, In some patients, it even supported repositioning. In six patients, the fractures were of the anterior collum and six fractures were fractures of both colla. The mean time span of follow-up was 13.1 months, the minimum being 4.5 and the maximum 23 months. Results: In most patients, the intra- and postoperative computed tomographic scans showed anatomically correct placement of the plate, thus confirming the correct repositioning of the bone. Routine follow-ups are part of the hospital's postsurgical care system for acetabular fractures; these revealed no secondary dislocation or loosening of the plate. The radiological examination showed consolidation of the fractures after a mean period of twelve weeks. A full year after the initial procedure, no implant-specific complications were observed. Revision surgery was necessary in one patient due to bleeding five days after surgery. In another patient, necrosis of the femoral head necessitated total hip replacement ten weeks after the first surgical intervention. In summary, the concept of the plate proved to be successful in its first case series. Summary: In spite of increasing surgical expertise and the refinements of standard approaches, there is a recognisable shift in acetabular fractures from mainly posterior fracture patterns to fractures of the anterior column. The new acetabulum wing plate takes these factors into account and is an implant designed to address the anterior aspects of the acetabulum. The outcome of the first application is promising and the acetabulum wing plate produces satisfactory results in our patients.

P15. Implant-specific complications in breast reconstruction – A single surgeon's experience

Introduction: Subpectoral tissue expander and implant based breast reconstruction involves the insertion of a tissue expander under the pectoralis major muscle and overlying skin. It is inflated over a number of months and eventually replaced with a definitive implant. Expander/implant based reconstruction can be undertaken at the time of mastectomy (immediate reconstruction) or at a later date (delayed reconstruction). Implant related complications include implant displacement, infection or rupture.

286. Implant-specific Complications in Breast Reconstruction- a Single Surgeon's Experience

Background: Subpectoral tissue expander and implant based breast reconstruction involves the insertion of a tissue expander under the pectoralis major muscle and overlying skin, which is gradually inflated with saline over a number of months. Following this, the expanders are replaced with definitive implants.

High-Flexion versus Conventional Total Knee Arthroplasty: A 5-Year Study

To compare mid-term outcomes of a high-flexion prosthesis with a conventional prosthesis. Records of 107 consecutive patients who underwent total knee arthroplasty (TKA) for primary osteoarthritis by a single surgeon were reviewed. 21 men and 36 women (mean age, 65 years) used a high-flexion prosthesis (NexGen CR-Flex Mobile, Zimmer), whereas 38 men and 12 women (mean age, 67 years) used a conventional prosthesis (Genesis II, Smith & Nephew) that preserves the posterior cruciate ligament, with mobile-bearing polyethylene inlay. The Knee Society knee and functional scores and the range of motion (especially maximum passive flexion) were assessed. Radiographs were evaluated to identify radiolucent lines at the bone cement interface, patella tracking, tibiofemoral alignment, and implant positioning. The mean follow-up period was 68 (range, 51- 70) months. In terms of the mean Knee Society scores and range of motion, the difference between groups was not significant (p>0.05), but the improvement in both groups after TKA was significant (p<0.005). Respectively in the high-flexion and conventional TKA groups, 2 and one of the patients developed deep vein thrombosis and were treated with anticoagulants for 3 months. One and 5 of the patients had an unsatisfactory range of motion (<60º) in week 1, which was resolved with mobilisation under general anaesthesia in combination with a peridural catheter for analgesia. No patient developed implant-specific complications such as aseptic loosening (osteolysis, progressive radiolucent lines, implant deviation) or dislocation of the polyethylene insert. The high-flexion prosthesis revealed no significant advantages over the conventional prosthesis in terms of the Knee Society scores and range of motion. Long-term studies are needed to determine whether the high-flexion implant is superior to the conventional implant in terms of polyethylene wear and aseptic loosening.

Minimum Five-year Follow-up Results of Single-Radius, High-Flex Posterior-Stabilized TKA

We studied 75 primary total knee arthroplasties (TKAs) performed using a single-radius, high-flex posterior-stabilized insert design with a minimum 5-year follow-up to document its implant specific complications and clinical results. Nonprogressive osteolysis was observed at zone 4 of the femoral component in 6 knees (8%) and at zone 1 of the tibial component in 6 knees (8%). However, no complications associated with high flexion designs, such as early aseptic loosening, were observed.Preoperatively, mean Knee Society Knee Score and Knee Society Function Score were 55.1 and 45.5, respectively (range, 10-83 and 20-80, respectively). At last follow-up, mean Knee Society Knee Score and Knee Society Function Score improved to 94.9 and 85.9, respectively (range, 70-100 [P<.0001] and 45-100 [P<.0001], respectively). Mean maximal flexion was 122.1 degrees (range, 90 degrees -140 degrees ) and mean range of motion (ROM) was 110.3 degrees (range, 80 degrees -135 degrees ) preoperatively, and these values improved to 128.9 degrees (range, 110 degrees -150 degrees [P<.0001]) and 127.8 degrees (range, 110 degrees -150 degrees [P<.0001]), respectively, at last follow-up. Preoperative ROM was found to be the only factor significantly correlated with postoperative ROM at last follow-up by univariate (P=.0020) and multivariate analysis (P<.0067). Accordingly, clinical results were comparable to previous reports of high-flex implants without implant-specific complications.

A Rare Complication of Ceramic-on-Ceramic Bearings in Total Hip Arthroplasty

Each year, approximately 217 000 primary total hip arthroplasties (THAs) are performed in the United States (National Center for Health Statistics, 2003). This number is expected to increase as our population ages, and the indication for THA expands to younger and more active patients. Efforts are continually being made to improve implant design and, ultimately, patient outcomes. One area in particular that has undergone tremendous change is bearing surface technology. Ceramic-on-ceramic technology has gained widespread popularity in young patients because of its improved wear characteristics and durability. Bearing surface advancement must be tempered with analysis of implant-specific complications. We report a case of an audible hip complication after the use of ceramic components in THA.

Outcomes Associated with Ganciclovir Implants in Patients with AIDS-Related Cytomegalovirus Retinitis

To investigate complications associated with ganciclovir implants used to treat AIDS-related cytomegalovirus (CMV) retinitis, and to identify factors that predict poor outcomes. Retrospective chart review. Consecutive patients with AIDS-related CMV retinitis from 3 clinical facilities who underwent implantation procedures during the period January 1, 1995 through December 31, 2001. Baseline for each patient was the date of the first implantation procedure performed during the study period by one of the facilities' surgeons (index implant). Medical and ophthalmological data were collected at baseline and at specific time points after baseline. The dates on which additional implantation procedures were performed and the dates on which complications or vision loss were identified were also recorded. Relationships between potential risk factors and outcomes were studied by Kaplan-Meier analyses and Cox proportional hazards regression models. Primary outcome measures included postoperative complications specifically related to or possibly related to ganciclovir implants. A secondary outcome measure was vision loss after implantation procedures. The charts of 174 patients (one study eye per patient; 279 implants) were reviewed. Median follow-up was 14.4 months (range, 0-7 years). Complications specifically related to implants occurred throughout follow-up at a rate of 0.064 events per patient-year. Complications possibly related to implants occurred at an overall rate of 0.377 per patient-year, but seemed to be more common during the first 2 years after baseline. During the first 2 years of follow-up, retinal detachments occurred at a rate of 0.156 events per patient-year. The cumulative risk of vision loss (> or =3 lines of Snellen visual acuity) at 7 years was 70%. Poor outcomes were associated with disease factors (size and activity of lesions), lack of highly active antiretroviral therapy (HAART), and lack of HAART-associated immune reconstitution, but not with surgical factors or implant-specific complications. Complications specifically associated with ganciclovir implants can occur many years after implantation procedures, but the incidence of such complications is low. Continued vision loss is not attributable directly to complications of implants in most cases. This information will help in planning of treatment strategies for CMV retinitis in long-term survivors of human immunodeficiency virus disease.

Innovation in der Unfallchirurgie 1975 bis 1996: über den Methodenwechsel in 21 Jahren

The traumatologic operation technique is reported over a time period of 21 years. Concerning the treatment of the intertrochanteric femur fracture, a development from the Ender nailing to the dynamic hip screw treatments. In a recent study investigating 217 dynamic hip screws treatments, 4.5% implant-specific complications were found. In the 1970s, fractures of the radius almost exclusively were treated conservatively, nowadays in most cases they are treated operatively. There was a change in the treatment of instable fractures of the spine during the study period: from the conservative treatment with a plaster cast immobilisation for months, the plate osteosynthesis, to the application of an internal fixation, the `fixateur interne'. The recent results of the ‘fixateur interne’ application in instable vertebral fractures do not justify the replacing of the dorsal by the combined dorso-ventral approach.