[Acetabular metastatic defect reconstruction using the modular revision support cup MRS-C]. / Rekonstruktion von metastasenbedingten Defekten des Azetabulums mittels der MRS-C-Abstützschale.

OBJECTIVE: Stabilization of metastatic acetabular defects with a bone cement-augmented revision support cup for remobilization of oncological patients in advanced cancer stages. INDICATIONS: Metastatic acetabular defects (Metastatic Acetabular Classification, MAC 2-4) in patients with a prognostic medium or long-term survival. CONTRAINDICATIONS: Highly limited survival due to metastatic disease (< 6 weeks). Local bone or soft tissue infection. Primary bone tumor with curative treatment option. Advanced pelvic discontinuity. Recent wound compromising systemic therapy. SURGICAL TECHNIQUE: Standard hip approach. Curettage of the metastatic defect and careful reaming of the acetabulum before insertion of the cup. Predrilling of the dome und flange screws before application of the bone cement through the center hole of the implant and filling of the acetabular defect. Complete insertion of the screws for compound osteosynthesis. Implant of a modular inlay or dual mobility system. POSTOPERATIVE MANAGEMENT: Full weight bearing or mobilization with two crutches according to the level of pain. Adjuvant local radiation therapy after wound consolidation. Continuation of systemic therapy according to tumor board decision. RESULTS: Between 2012 and 2019, we treated 14 patients with metastatic acetabular defects using the modular revision support cup "MRS-TITAN® Comfort", MRS-C, Peter Brehm GmbH, Weisendorf, Germany) at our institution. Mean Harris Hip Score improvement was 23.2 with a mean patient's survival of 9.7 months due to the reduced cancer-related prognosis; 13 of the 14 implants endured the patient's prognosis. One implant had to be removed due soft tissue defect-related periprosthetic joint infection.

[Reconstruction of the extensor apparatus with advanced structural defects in knee revision arthroplasty]. / Rekonstruktion des Streckapparates bei fortgeschrittenen Defekten in der Knierevisionsendoprothetik.

OBJECTIVE: Restoration of the extensor apparatus in the case of advanced tendon defects as part of revision total knee arthroplasty (TKA). Reconstruction and augmentation using vascularized gastrocnemius muscle and tendon. INDICATIONS: Advanced degeneration of the extensor apparatus (patella tendon; quadriceps tendon) with or without discontinuity, following revision arthroplasty. CONTRAINDICATIONS: Persistent infection or pending TKA revision. Damaged gastrocnemius or soleus muscle or Achilles tendon. SURGICAL TECHNIQUE: Extension of the surgical TKA-access medial-distally. Separation of the medial gastrocnemius muscle along the raphe and preparation of the distal tendon from the soleus portion. Transposition into the defect site, augmentation or reconstruction of the defect by double turn of the gastrocnemius tendon. The muscle belly serves to adequately cover the tendon as well as the ventral knee joint. Mesh coverage of the muscle. POSTOPERATIVE MANAGEMENT: Immobilization of the knee and ankle for 10 days until mesh graft healing. Stepwise increasing flection of the knee with 30°/60°/90° every 2 weeks. Total weight bearing with secured full extended knee, no weight bearing with flexed knee for 6 weeks. RESULTS: In 9 patients, 3 with complete rupture of the patellar tendon, 5 with destruction of the extensor apparatus, and 1 patient with rupture of the quadriceps tendon following TKA revision, good functional results were achieved with active extension of the knee joint and standing/gait stability 6 months after surgery.

[Reconstruction of tibial metaphyseal defects with artificial components in revision arthroplasty (GenuX MK System)]. / Rekonstruktion tibialer metaphysärer Defekte im Revisionsfall mit metallischen Metaphysenkomponenten (GenuX MK-System).

OBJECTIVE: Restoration of knee function by using tibial metaphyseal components in advanced metaphyseal bone defects after multiple bone-damaging revision surgery on the knee joint. INDICATIONS: Advanced tibial metaphyseal bone defects (Anderson Orthopaedic Research Institute [AORI] IIb and III defects) in revision arthroplasty of the knee joint. CONTRAINDICATIONS: Persistent or current joint infection, general infection (e.g., pneumonia), nonreconstructable insufficient extensor apparatus. SURGICAL TECHNIQUE: Standard access including existing skin scars, arthrotomy, removal of cement spacer if necessary and removal of multiple tissue samples; preparation of femur first, followed by preparation of the tibia. Referencing the tibial rotation and joint line height. Tibial osteotomy referenced intramedullarily. Determination of the metaphyseal defect size and choice of component size. Positioning of the rasp guide for the preparation of the metaphyseal component (sleeve); gradual preparation of the bed for the metaphyseal component. Afterwards the prepared component at the desired depth (when using augments +5 or +10 mm accordingly 5 or 10 mm above the tibial plateau) is left and the tibial plateau is fixed on the embedded sleeve. Test coupling, control of the implant position and the height of the joint line radiologically. If satisfactory the definitive implants accordingly to the components of used implants before can be implanted. POSTOPERATIVE MANAGEMENT: Full weight bearing. Regular wound control; limitation of the degree of flexion only with weakened or reconstructed extensor apparatus. RESULTS: Between May 2018 and August 2019, 14 metaphyseal tibial components were implanted in 14 patients. The mean follow-up was 10.4 months. The follow-up included clinical examination, KSS (Knee Society Score) and an X­ray and failure analysis. A significant improvement in range of movement from 75 ± 16° to 100 ± 14° (p < 0.01) was achieved. The KSS improved significantly from 78 ± 12 points preoperatively to 137 ± 23 points postoperatively. Two patients complained of persistent pain after exercise (walking distance >200 m) after 6 months; tibial shaft pain was negated by all patients. The group examined afterwards showed an implant survival rate of 100% in the observation interval.

[Use of an new modular revision arthroplasty system for the knee reconstruction]. / Einsatz eines neuen modularen revisionsendoprothetischen Systems zur Kniegelenksrekonstruktion.

OBJECTIVE: Reconstruction of stable knee joint kinematics using modular axis-guided revision implants after failed knee arthroplasty surgery. INDICATIONS: Revision implant for bone defects (type Anderson Orthopaedic Research Institute [AORI] III) in case of revision arthroplasty. Primary implant in case of mediolateral instability (>grade I) or multidirectional instability. CONTRAINDICATIONS: Persistent or current joint infection, general infection (e.g. pneumonia), missing metaphysis femoral and/or tibial, insufficient extensor apparatus. SURGICAL TECHNIQUE: Standard approach extending the previously used skin incision. Arthrotomy, synovectomy and collection of multiple samples for microbiological and histopathological analyses. Preparation of the femur with reamers of increasing diameter. Subsequently, a reference stem is anchored and after referencing the correct rotation and joint line height; the femoral osteotomy is performed after fixation of the 5­in­1 cutting block. Following the femoral osteotomy, the box of the femoral prosthesis is prepared. In addition, the tibia is prepared using an intramedullary reference system. Level of constraint and additional tibial augmentation is chosen according to the amount of defect bone and according to ligament stability. POSTOPERATIVE MANAGEMENT: Full load bearing; standard wound control and sterile dressings; limitation of active/passive range of motion only in case of weakened extensor apparatus. RESULTS: Between 03/2011 and 05/2018, a total of 48 patients underwent revision arthroplasty using the described system. The mean follow-up was 24 months (range 21-35 months). In 30 of the 48 cases, a rotating hinge variant was implanted, while in 18 cases a semiconstrained variant was implanted. Indications to revision arthroplasty: infection (n = 22), aseptic loosening (n = 11), instability (n = 11), periprosthetic fracture (n = 3) and PMMA allergy (n = 1). In 11 cases, revision had to be performed due to persistent infection (n = 6) and aseptic loosening (n = 5): 9 cases could be successful treated by a two-step revision procedure, while in 2 cases it was necessary to perform an arthrodesis. The 2­year implant survival rate was 77%.

[Distal femur replacement in extensive defects of the distal femur in revision arthroplasty]. / Distaler Femurersatz bei ausgedehnten femoralen Defekten in der Revisionsendoprothetik.

OBJECTIVE: Use of distal femur replacement implants in advanced bone defects after multiple bone-damaging revision surgery on the knee joint. INDICATIONS: Advanced femoral bone defects (AORI IIb and III defects) in revision arthroplasty of the knee joint. CONTRAINDICATIONS: Persistent or current joint infection, general infection, defect and/or nonreconstructable insufficient extensor apparatus. SURGICAL TECHNIQUE: Standard access including existing skin scars, arthrotomy, removal of cement spacer if necessary and removal of multiple tissue samples; preparation of tibia first to define the joint line, then preparation of the femur. Determining the resection height of the remaining femur corresponding to the preoperative planning. Gradual drilling using flexible medullary drills and then preparation by femoral rasps. Two stem systems are available for coupling to the distal femur (MUTARS). First there is the standard MUTARS stem (available lengths of 90, 120 and 160 mm); if longer shafts are required, so-called revision shaft (RS) stems are necessary (stems available in 150, 200 and 250 mm). In case of extensive femoral defects extension sleeves in different lengths can be used to reconstruct the femur. After preparation the implant position and the joint line height is checked. POSTOPERATIVE MANAGEMENT: Full weight bearing, in case of existing bony defects possibly partial load of a maximum of 10 kg für 6 weeks; regular wound control; limitation of the degree of flexion only with weakened or reconstructed extensor apparatus. RESULTS: Between February 2015 and August 2018, a total of 34 distal femurs were implanted. In 19 patients, the implantation was performed after septic and aseptic loosening of a knee prosthesis. All patients had an intraoperative AORI III defect of the femur. Of the 19 patients who underwent a distal femur implantation, 7 had to be revised due to a persistent infection; 4 of these 7 patients had to be revised several times and, finally, had a conversion to a knee arthrodesis. One patient had to undergo a revision with a stem change due to a secondary aseptic loosening of the cemented stem. The mean follow-up period was 11.2 months (range 4-29 months). The follow-up included clinical examination, KSS (Knee Society Score) and X­ray analysis. A significant improvement in range of motion from 65 ± 16° to 83 ± 14° (p < 0.01) was noted. The KSS improved significantly from 69 ± 9 points preoperatively to 115 ± 15 points postoperatively. Four patients complained of persistent symptoms during exercise after 9 months; femoral shaft pain was denied by all patients. After about 11 months, an implant survival rate of 73.7% was observed in the patient collective.

[Challenges of discharge management in geriatric traumatology : Example of an integrated orthogeriatric service]. / Herausforderungen des Entlassmanagements in der Alterstraumatologie : Beispiel einer integrierten traumatologisch-geriatrischen Komplexbehandlung.

BACKGROUND: Geriatric patients are currently responsible for almost one third of all emergency hospital admissions. An increase of 50% is expected in the next decade. This age redistribution poses new challenges for inpatient care and discharge management. The requirements of an orthopedic trauma surgery clinic in the care of this patient group can be clarified with the help of this first collaboratively created geriatric orthopedic trauma surgery complex treatment unit of a university hospital. OBJECTIVE: What influence do age and delirium have on discharge management, length of inpatient stay and discharge destination in a geriatric cohort? MATERIAL AND METHODS: All patients who received inpatient treatment as part of the orthopedic trauma surgery geriatric complex treatment (GKB) between May 2017 and December 2019 were evaluated. An analysis of the demographics, length of inpatient stay, discharge destinations and evaluation of the Barthel index collected on admission and discharge, the mini-mental state examination (MMSE) and the geriatric depression scale (GDS) were carried out. RESULTS: Out of 312 patients, 110 men and 193 women with a median age of 81 years, 77 patients (24.6%) showed delirium when enrolled in the GKB and 39 (12.5%) dementia. Older patients presented more often with delirium than younger people (p = 0.013), especially those aged 70-79 years (p = 0.037). Dementia patients suffered more frequently from postoperative delirium (p < 0.01). The mean hospital stay was 17.79 days (±4.6 days). The GKB was regularly completed in 60.7% of all cases and 39.3% patients dropped out early. Patients with delirium were discharged significantly less often into their own home but into short-term care or nursing homes (p = 0.038). A general correlation between delirium development and the discharge destination was noticeable (p = 0.004). CONCLUSION: Patients with dementia are more likely to develop delirium postoperatively, which leads to an increase in the length of inpatient stay, an increase in treatment costs and more work for the discharge management team. In addition, the discharge to the patients' home is impaired by delirium, which means that the growing need for places in short-term care and nursing homes also creates socioeconomic burdens.

Analysis of synovial biomarkers with a multiplex protein microarray in patients with PJI undergoing revision arthroplasty of the hip or knee joint.

INTRODUCTION: Diagnosing a (low-grade) periprosthetic joint infection (PJI) after hip or knee arthroplasty remains a diagnostic challenge. The aim of this study was to evaluate the utility of using a novel multiplex protein microarray system for synovial biomarkers in determining PJI in patients undergoing revision knee or hip arthroplasty. MATERIALS AND METHODS: The individual synovial fluid levels of 12 cytokines (IL-1b, IL-2, IL-4, IL-5, IL-6, IL-8, IL-10, IL-12, IL-17, GM-CSF, TNF-α, and INF-γ) were analysed with a novel multiplex protein microarray system in 32 patients undergoing revision hip (n = 22) or knee (n = 10) arthroplasty. Cases were classified into septic and aseptic groups on basis of pre- and interoperative findings: [PJI (n = 14) vs. non-PJI (n = 18)]. Receiver operator characteristic (ROC) curves were calculated to assess the discriminatory strength of the individual parameters. A multiple regression model was used to determine the utility of using a combination of the tested cytokines to determine the infection status. RESULTS: The levels of all of the evaluated cytokines were significantly elevated in the PJI-group. Best sensitivity and specificity were found for IL-6, followed by IL-1b, IL-10, and IL-17. The multiple regression models revealed a combination of IL-2, IL-4, IL-5, IL6, lL-12, and GM-CSF to be associated with the best sensitivity (100%) and specificity (88.9%) for a cut-off value of 0.41, with a likelihood ratio of 9.0. CONCLUSION: Analysis of individual synovial fluid cytokine levels showed both high sensitivity and high specificity in diagnosing PJI. A combined model using several cytokines showed even higher sensitivity and specificity in diagnosing PJI and could thus be a useful predictive tool to determine the probability of PJI in patients with a painful prosthesis. LEVEL OF EVIDENCE: Diagnostic IV.

Dynamic intraligamentary stabilization: novel technique for preserving the ruptured ACL.

PURPOSE: Replacement of the torn anterior cruciate ligament (ACL) with a transplant is today`s gold standard. A new technique for preserving and healing the torn ACL is presented. HYPOTHESIS: a dynamic intraligamentary stabilization (DIS) that provides continuous postinjury stability of the knee and ACL in combination with biological improvement of the healing environment [leucocyte- and platelet-rich fibrin (L-PRF) and microfracturing] should enable biomechanically stable ACL self-healing. METHODS: Ten sportive patients were treated by DIS employing an internal stabilizer to keep the unstable knee in a posterior translation, combined with microfracturing and platelet-rich fibrin induction at the rupture site to promote self-healing. Postoperative clinical [Tegner, Lysholm, International Knee Documentation Committee (IKDC), visual analogue scale patient satisfaction score] and radiological evaluation, as well as assessment of knee laxity was performed at 6 weeks, 3, 6, 12, and 24 months. RESULTS: One patient had a re-rupture 5 months postoperative and was hence excluded from further follow-ups. The other nine patients presented the following outcomes at 24 months: median Lysholm score of 100; IKDC score of 98 (97-100); median Tegner score of 6 (range 9-5); anterior translation difference of 1.4 mm (-1 to 3 mm); median satisfaction score of 9.8 (9-10). MRI showed scarring and continuity of the ligament in all patients. CONCLUSIONS: DIS combined with microfracturing and L-PRF resulted in stable clinical and radiological healing of the torn ACL in all but one patient of this first series. They attained normal knee scores, reported excellent satisfaction and could return to their previous levels of sporting activity. LEVEL OF EVIDENCE: Case series with no comparison group, Level IV.

[Operative treatment of congenital hip osteoarthritis with high hip luxation (Crowe type IV)]. / Die operative Versorgung der sekundären Coxarthrose bei kongenitaler Hüftluxation (Crowe Typ IV).

OBJECTIVE: The aim of the therapy is mechanical and functional stabilization of high dislocated hips with dysplasia coxarthrosis using total hip arthroplasty (THA). INDICATIONS: Developmental dysplasia of the hip (DDH) in adults, symptomatic dysplasia coxarthrosis, high hip dislocation according to Crowe type III/IV, and symptomatic leg length inequality. CONTRAINDICATIONS: Cerebrospinal dysfunction, muscular dystrophy, apparent disturbance of bone metabolism, acute or chronic infections, and immunocompromised patients. SURGICAL TECHNIQUE: With the patient in a lateral decubitus position an incision is made between the anterior border of the gluteus maximus muscle and the posterior border of the gluteus medius muscle (Gibson interval). Identification of the sciatic nerve to protect the nerve from traction disorders by visual control. After performing trochanter flip osteotomy, preparation of the true actetabulum if possible. Implantation of the reinforcement ring, preparation of the femur and if necessary for mobilization, resection until the trochanter minor. Test repositioning under control of the sciatic nerve. Finally, refixation of the trochanteric crest. POSTOPERATIVE MANAGEMENT: During hospital stay, intensive mobilization of the hip joint using a continuous passive motion machine with maximum flexion of 70°. No active abduction and passive adduction over the body midline. Maximum weight bearing 10-15 kg for 8 weeks, subsequently, first clinical and radiographic follow-up and deep venous thrombosis prophylaxis until full weight bearing. RESULTS: From 1995 to 2012, 28 THAs of a Crow type IV high hip-dislocation were performed in our institute. Until now 14 patients have been analyzed during a follow-up of 8 years in 2012. Mid-term results showed an improvement of the postoperative clinical score (Merle d'Aubigné score) in 86 % of patients. Good to excellent results were obtained in 79 % of cases. Long-term results are not yet available. In one case an iatrogenic neuropraxia of the sciatic nerve was observed and after trauma a redislocation of the arthroplasty appeared in another case. In 2 cases an infection of the THA appeared 8 and 15 months after index surgery. No pseudoarthrosis of the trochanter or aseptic loosening was noticed.

Hip resurfacing using a modified lateral approach with limited splitting of the gluteus medius muscle results in significant impairment of hip abductor strength.

BACKGROUND: A lateral, transgluteal approach for hip resurfacing carries the risk of approach-related weakening of the hip abductors due to unsuccessful re-adaptation of the gluteal muscles to the greater trochanter or to injury to the inferior nerve branch of the superior gluteal nerve. OBJECTIVE: We investigated whether hip resurfacing using a soft tissue-sparing, modified transgluteal approach with limited cranial splitting of the gluteus medius muscle reduces hip abductor strength and the risk of approach-related injury to the superior gluteal nerve. METHODS: Thirty-one patients (14 female, 17 male; mean age 53.5 ± 5.2 years) underwent hip resurfacing using a modified transgluteal approach with limited cranial splitting of the gluteus medius muscle. Nerve conduction signals were measured by surface electromyography (EMG), hip abductor strength by isokinetic testing a mean 36.2 months (± 11 mos) after surgery. The unoperated side was used as control. RESULTS: Surface EMG disclosed no neural lesions of the inferior branch of the superior gluteal nerve. Isokinetics revealed a significant reduction in muscle strength on the operated versus the contralateral side. CONCLUSIONS: Even a limited incision of the gluteus medius muscle resulted in significant impairment of hip abductor strength 2.5 years after surgery.