Dislocation of primary total hip arthroplasty: Analysis of risk factors and preventive options.

Total hip arthroplasty (THA) is one of the most successful elective operations in orthopedic surgery for improving pain and functional disability in patients with end-stage joint disease. However, dislocation continues to be a troublesome complication after THA, as it is a leading cause of revision and is associated with substantial social, health, and economic costs. It is a relatively rare, usually early occurrence that depends on both the patients' characteristics and the surgical aspects. The most recent and important finding is the special attention to be given preoperatively to spinopelvic mobility, which is closely related to the incidence of dislocation. Consequently, clinical and radiographic assessment of the lumbar spine is mandatory to identify an altered pelvic tilt that could suggest a different positioning of the cup. Lumbar spinal fusion is currently considered a risk factor for dislocation and revision regardless of whether it is performed prior to or after THA. Surgical options for its treatment and prevention include the use of prostheses with large diameter of femoral head size, dual mobility constructs, constrained liners, and modular neck stems.

Release of gentamicin and vancomycin from preformed spacers in infected total hip arthroplasties: measurement of concentrations and inhibitory activity in patients' drainage fluids and serum.

Gentamicin (G) and vancomycin (V) concentrations in drainage fluids obtained from patients during the first 24 hours after implantation of antibiotic-loaded polymethylmethacrylate (PMMA) spacers in two-stage revision of infected total hip arthroplasty were studied. The inhibitory activity of drainage fluids against different multiresistant clinical isolates was investigated as well. Seven hips were treated by implantation of industrial G-loaded spacers. Vancomycin was added by manually mixing with PMMA bone cement. Serum and drainage fluid samples were collected 1, 4, and 24 hours after spacer implantation. Antibiotics concentrations and drains bactericidal titer of combination were determined against multiresistant staphylococcal strains. The release of G and V from PMMA cement at the site of infection was prompt and effective. Serum levels were below the limit of detection. The local release kinetics of G and V from PMMA cement was similar, exerting a pronounced, combined inhibitory effect in the implant site. The inhibitory activity of drainage fluids showed substantial intersubject variability related to antibiotic concentrations and differed according to the pathogens tested. Gentamicin and vancomycin were released from temporary hip spacers at bactericidal concentrations, and their use in combination exerted strong inhibition against methicillin-resistant S. aureus and Coagulase Negative Staphylococci strains.

Long-term results of femoral revision with the Wagner Self-Locking stem.

Femoral revision total hip arthroplasty may be a complex procedure due to extensive periprosthetic bone loss. Fluted, tapered stems provide secure axial and rotational stability in the distal femur. We retrospectively evaluated the long-term outcome of the cementless Wagner Self-Locking prosthesis (Sulzer Orthopedics Ltd, Winterthur, Switzerland). From 1992 to 1998, 68 consecutive femoral revisions were performed in 66 patients using the Wagner tapered stem. Twenty-five patients deceased for unrelated causes without additional surgery. The studied group consisted of 41 hips in 41 patients, 12 males and 29 females, aged from 29 to 80 years (mean 61 years). Thirty-five hips (85.4%) included severe deficiency of bone stock. A transfemoral approach was carried out in 32 cases (78%). Bone grafting was never supplemented. Average follow-up was 13.9 years (range 10.4 to 15.8 years). Clinical evaluation was performed using Harris Hip Score (HHS). Osseointegration of the stem and progression of periprosthetic bone remodelling were assessed radiographically. Five stems required rerevision because of deep infection (2), progressive subsidence (2) complicated by hip instability and head-neck disassembly, and old dislocation following acetabular component failure (1). Four hips (9.7%) dislocated, and 8 stems (19.5%) subsided significantly. Average HHS improved from 33 points preoperatively to 75 points at the latest follow-up examination (p < 0.001). Thirty-three of the 36 unrevised stems (91.7%) had radiographic evidence of bone ingrowth. A constant or decreased resorption of the femoral bone was detected in 34/36 patients (94.4%). The cumulative survival rates at 15.8 years with femoral revision for any reason and for stem failure as the end points were 92.0% and 96.6%, respectively. The current study documents the efficacy of distal fixation to the diaphysis in revision of bone-deficient femoral components, supporting the use of tapered, fluted stems. Higher-risk complications (dislocation, subsidence) should be minimized by the development of modular stems.

Diagnosis of periprosthetic hip infection: a clinical update.

Periprosthetic joint infection (PJI) is a serious complication following hip arthroplasty, which is associated with significant health cost, morbidity and mortality. There is currently no consensus in the optimal definition of PJI, and establishing diagnosis is challenging because of conflicting guidelines, numerous tests, and limited evidence, with no single test providing a sensitivity and specificity of 100%. Consequently, the diagnosis of PJI is based on a combination of clinical data, laboratory results from peripheral blood and synovial fluid, microbiological culture, histological evaluation of periprosthetic tissue, radiological investigations, and intraoperative findings. Usually, a sinus tract communicating with the prosthesis and two positive cultures for the same pathogen were regarded as major criteria for the diagnosis, but, in recent years, the availability of new serum and synovial biomarkers as well as molecular methods have shown encouraging results. Culture-negative PJI occurs in 5-12% of cases and is caused by low-grade infection as well as by previous or concomitant antibiotic therapy. Unfortunately, delay in diagnosis of PJI is associated with poorer outcomes. In this article, the current knowledge in epidemiology, pathogenesis, classification, and diagnosis of prosthetic hip infections is reviewed.

Cemented and uncemented stems for displaced femoral neck fracture in the elderly. Retrospective study with a minimum 1-year follow-up.

BACKGROUND AND AIM: Displaced femoral neck fracture (FNF) is a common and significant health issue especially in older population because of the high rates of mortality and complications. The standard surgical treatment is total or partial hip replacement, including a cemented or uncemented stem. The cemented prosthesis is considered the safer option because of a lower rate of periprosthetic fractures (PPFs) as well as an actually reduced risk of bone cement implantation syndrome (BCIS). This retrospective study aims to assess the efficacy and safety of cemented versus uncemented femoral stem for FNF in patients ≥70 years. METHODS: 139 patients affected by displaced FNF underwent hip replacement, receiving 89 cemented (64%) and 50 uncemented (36%) stems. Inclusion criteria were: ≥70 years of age, an ICD-9-CM diagnose code 820.00, 820.01, 820.02, 820.03, 820.10, 820.8, and a minimum 1-year follow-up. A p value <0.05 was considered statistically significant. RESULTS: Surgical time, overall perioperative complication rate with a particular focus on the thromboembolic events, and PPFs incidence were evaluated comparing cemented and uncemented group. No difference in duration of surgery was found. Intraoperative complications were not detected. Pulmonary embolism and deep vein thrombosis were observed each in 1 case of cemented prosthesis. Periprosthetic femoral fractures occurred only in the uncemented group postoperatively, with a statistically significant difference (p<0.05). CONCLUSIONS: The low incidence of BCIS and the higher risk of postoperative PPFs in cemented and uncemented stems, respectively, suggest that the use of cementation is a safer procedure.

A minimum of 10-year follow-up of the Burch-Schneider cage and bulk allografts for the revision of pelvic discontinuity.

Eighteen consecutive hips with pelvic discontinuity and associated periprosthetic bone deficiency were treated with bulk allografts and Burch-Schneider antiprotrusio cage. Clinical and radiographic follow-up was performed at an average of 13.5 (range, 10.5-16.6) years. Three cages required re-revision because of infection (1) and aseptic loosening (2). Average Harris hip score improved from 31.9 to 77.0 points (P < .001). A severe resorption of the bone graft occurred in 2 hips. The stability of the cage was detected in 13 cases. The cumulative survival rate at 16.6 years with acetabular revision for any reason, radiographic loosening, or unhealing of the discontinuity as the end point was 72.2%. The use of Burch-Schneider cage and bulk allografts is an effective technique for the treatment of pelvic discontinuity.

Late intraprosthetic dislocation of a monoblock dual-mobility cup cemented into a well-fixed cementless acetabular shell. A case report.

Intraprosthetic dislocation (IPD) is a specific implant-related complication of dual mobility (DM) implants, which is defined as a dissociation of polyethylene (PE) liner from the femoral head. We report a unique case of  late IPD of a monoblock DM cup cemented into a well-fixed cementless acetabular shell for recurrent dislocation of total hip arthroplasty (THA). A 77-year-old woman was admitted to our department for acute right hip pain, functional impairment and inability to bear weight without any trauma. Three years earlier, she underwent revision THA for recurrent dislocation with a monoblock DM cup cemented into a well-fixed cementless acetabular shell according to the "double-socket" technique. Three months after that revision the patient experienced an anterior THA dislocation, which was managed by closed reduction under sedation in the emergency room. No additional episodes of prosthesis instability occurred. Upon admission, radiographic evaluation showed  right THA dislocation. X-rays performed  after closed reduction revealed eccentric positioning of the head inside the cup, and a direct contact between the metal head and the cup was revealed by subsequent CT scan, confirming the suspicion of IPD. The patient underwent revision surgery, during which the PE liner was found lodged within the cup in a subluxated position, disassembled from the inner head. Both the acetabular cup and modular femoral stem proved well-fixed and impossible to remove, therefore they were retained. The explanted DM components were replaced with new ones of the same size and, thanks to the femoral neck's modular nature, it was substituted with a longer one, which resulted in improved stability against intraoperative stress maneuvers. The postoperative course was uncomplicated. At 1-year follow-up, the patient had a good functional recovery.

Six-year follow-up of a preformed spacer for the management of chronically infected total hip arthroplasty.

Antibiotic-loaded cement spacers are currently used in two-stage revision of septic total hip arthroplasty as temporary devices. Prolonged spacer implantation in infected shoulder has been described occasionally in poor candidates for reconstruction surgery (medically compromised and/or low-physical demand patients, deficient bone stock). Few papers previously reported the use of spacers in infected hip prosthesis as a permanent solution, but limited information is available on the medium-term behaviour. We detail medium-term clinical and radiographic follow-up of a preformed spacer in the management of a chronically infected hip arthroplasty in a 50-year-old female patient who did not undergo a second-stage surgery. Normalization of inflammatory markers was detected 3 weeks after surgery and persisted over time. Six years after surgery, the patient recovered a good range of motion and was able to walk pain free with assisted weightbearing. Remarkable radiological changes of the bone stock around the spacer stem have been assessed. New bone formation developed rapidly in the femur, leading to the consolidation of transfemoral osteotomy 6 months postoperatively. Two years after implantation, spontaneous and asymptomatic fatigue fracture in the mid-part of the stem occurred. Radiographs at 6 years showed a sufficient preservation of bone stock, though a slowly progressive resorption of the cortical femur around the stem was evident in the last year. In conclusion, prolonged spacer implantation seems to be not appropriate in septic hip arthroplasty as a permanent solution. In patients not undergoing a second-stage surgery, a careful and periodic monitoring is required to rule out possible and severe complications.

Fourth generation head fracture in ceramic-on-polyethylene bearing after hip revision surgery: a case report.

Fourth generation ceramic bearings (BIOLOX delta, CeramTec AG; Phlochingen, Germany) were developed to reduce wear debris and improve fracture resistance. A case of a fourth generation head fracture in ceramic-on-polyethylene (COP) coupling after hip revision surgery is reported. A 58-year-old man was admitted to our department for increasing hip pain following a direct trauma which occurred during skiing activity 4 months before. Six years earlier, he had undergone a right cementless revision surgery with a 36-mm BIOLOX delta femoral head on polyethylene liner for metallosis and foreign body reaction after primary total hip replacement for hip osteoarthritis. At admission, radiological evaluation revealed a fracture of ceramic femoral head requiring a new revision surgery. Extensive synovectomy, lavage and capsulectomy were performed. Both acetabular cup and femoral stem were well fixed with no damage of trunnion, and therefore they were retained. A 36-mm internal diameter polyethylene acetabular liner was inserted along a 36-mm BIOLOX delta head with a BioBall adapter XL. The postoperative course was uncomplicated. At 1-year follow-up, the patient had a complete functional recovery. To our knowledge, BIOLOX delta ceramic femoral head fracture after COP hip revision surgery has not been previously reported.

Stem modularity alone is not effective in reducing dislocation rate in hip revision surgery.

BACKGROUND: Dislocation is a serious complication following total hip arthroplasty (THA). Femoral revision using monoblock components has been associated with high incidence of subsidence and dislocation. Advantages of modular stems in THA have long been debated. The aim of this retrospective study is to assess the capability of an uncemented modular stem in decreasing the incidence of early dislocation subsequent to revision THA. MATERIALS AND METHODS: We evaluated the dislocation rate during the first 2 years following revision surgery in two groups of patients who were treated by implantation of a cementless tapered femoral prosthesis; a standard-modularity stem (Wagner SL) and an increased-modularity stem (Profemur R) were used, respectively, in 66 hips (group I, 64 patients) and 102 hips (group II, 97 patients). Group I consisted of 47 females and 17 males with average age of 66 years (range 29-84 years). Group II included 60 females and 37 males with average age of 70 years (range 48-89 years). RESULTS: Dislocation occurred in six hips (9.1%) of group I and in seven hips (6.8%) of group II (P = 0.401). Dislocations were observed early in both groups, except one hip in group II that dislocated 434 days postoperatively and required surgical reduction. All other dislocations were treated by closed reduction. No recurrence was observed. CONCLUSIONS: The use of an increased-modularity revision stem alone did not prove to be effective in reducing the risk of postoperative dislocation.

Open patellar tendon avulsion from tibial tuberosity after ACL reconstruction successfully treated with suture anchors.

Patellar tendon rupture after anterior cruciate ligament (ACL) reconstruction is a rare complication which usually occurs in the early postoperative period during rehabilitation. The management of open avulsions from tibial tuberosity has not been clearly defined yet. We describe a previously unreported case of traumatic and open patellar tendon avulsion from tibial tuberosity one year following ACL reconstruction in an elite football player which was successfully treated with suture anchors.

Late fracture of an old-generation modular neck in a titanium alloy femoral stem of a cementless total hip arthroplasty.

Neck-stem modularity gained recent popularity in hip arthroplasty for clinical advantages, and few complications have been reported. We describe an unusual two-stage failure of the bimodular neck of a cementless forged titanium alloy stem implanted 12 years before. The retrieved neck was forwarded to the manufacturer for metallurgic evaluation and failure analysis. Lengthening and bending of the superolateral aspect of the neck and double depression of the medial part prove that the prosthetic neck underwent a medial displacement and a varus rotation. The crack initiated from the superolateral corner of the fracture section, and the neck probably underwent two subsequent unstable configurations. The first horizontal part of the fracture occurred in the external surface as a result of physiological load carried on abnormal conditions of frictions. Due to increased oscillations, the end of the fracture section knocked against the inner aspect of the proximal hole of the stem, preventing further valgus displacement of the neck, which was moved forward. Consequently, the neck achieved a second unstable configuration, and the fracture propagated in the weaker direction creating a bent track. Finally, the neck broke unexpectedly as a result of the traumatic event. An incorrect placement into the femoral component during surgery was the initiation of the failure of the bimodular neck. The transitory but repeated interface motion between the neck and the stem induced a local surface irregularity acting as a starting point for crack propagation of fatigue fracture. Final failure followed a direct trauma.

Two-stage management of a spontaneous fracture of the greater trochanter through osteolytic lesions induced by polyethylene wear of a total hip arthroplasty. A case report.

Pelvic osteolysis induced by particulate debris derived from bearing surfaces is a well-known complication following total hip arthroplasty (THA). Atraumatic fractures of the greater trochanter (GT) associated with osteolytic lesions have been occasionally described. We present a case of a 71-year-old male patient who sustained an undisplaced fracture of the GT nine years following cementless metal-on-polyethylene THA. The fracture occurred through a 2.5-cm large osteolytic area, and no hip trauma was recorded. Conventional radiographs revealed peculiar signs of massive wear of the polyethylene acetabular liner (marked eccentricity of the prosthetic head and extensive osteolysis around the iliac screws), allowing to immediately conclude about the benign nature of the pathological fracture. To our knowledge, a two-stage management, planning conservative healing of the fracture and subsequent surgical replacement of the worn acetabular liner, has never been previously detailed.

Higher blood loss and transfusion requirement in surface arthroplasty versus conventional total hip replacement.

BACKGROUND AND AIM OF THE WORK: Surface replacement arthroplasty (SRA) is an alternative to stemmed total hip arthroplasty (THA) providing a femoral bone preserving procedure. Because of the wider surgical dissection, an increased blood loss could be expected. This retrospective study evaluates the transfusion requirement in two homogeneous groups of patients who underwent primary hip replacement electively. METHODS: Perioperative haematological data of 42 hip resurfacing procedures and 41 conventional cementless THAs were compared. The pre- and post-operative haemoglobin (Hb) levels and the amount of blood transfusions were registered. The median values were compared with use of the non-parametric Wilcoxon signedrank test. RESULTS: In the SRA group, a significantly increased (p<0.02) preoperative Hb concentration (13.1 g/dL, range 10.9 to 15.6) was detected in comparison with the THA group (12.5 g/dL, range 10.4 to 15.2). In the resurfacing procedures a median of 900 mL (range 600 to 1500) were transfused vs. 600 (range 300 to 1500) in the conventional THAs, demonstrating a significantly higher transfusion requirement (p<0.04). CONCLUSIONS: Whereas hip resurfacing is a femoral bone preserving alternative to conventional THA with comparable clinical and radiographic outcomes, higher blood loss and transfusion requirement may occur.

Post-traumatic cystic lesion following radius fracture: a case report and literature review.

BACKGROUND: Post-traumatic osseous cystic lesions represent a rare complication in children. Usually a post-fracture cyst is a lipid inclusion cyst, which is radiolucent and may be seen adjacent to a healing torus fracture. It is typically asymptomatic and appears just proximal to the fracture line within the area of subperiosteal new bone formation. CASE REPORT: We report a case of post-fracture cyst of the distal radius in an 8 year-old girl with spontaneous resolution. A fat-fluid level within the subperiosteal cystic lesion in MRI is a typical feature of post-traumatic cystic lesion in children. DISCUSSION AND CONCLUSION: MRI or CT scan is sufficient to confirm the diagnosis of post-traumatic cystic lesions without the need for further management other than reassurance and advise that they may occasionally cause discomfort but resolve with time.

Perioperative intravenous tranexamic acid reduces blood transfusion in primary cementless total hip arthroplasty.

BACKGROUND AND AIM OF THE WORK: Blood loss and transfusion requirements are common in total hip arthroplasty. Tranexamic acid is one of the most interesting options to reduce the need for blood transfusions in a variety of surgical settings. The aim of this study was to assess the efficacy of perioperative intravenous traxexamic acid regarding blood transfusion rate and volume of transfused blood without increasing adverse events after primary elective cementless total hip arthroplasty. METHODS: A comparative retrospective study was conducted in 86 healthy patients who had undergone primary cementless total hip artrhoplasty for severe joint diseases at a single institution. All surgical procedures were performed through an anterolateral Watson- Jones approach with the patient in supine position. Forty patients (TXA group) received tranexamic acid 1g as an intravenous bolus 10 minutes before skin incision and a further 1 g, diluted in 250 mL of saline solution, in continuous perfusion at 30 mL/h, following commencement of the surgery. Forty-six patients (control group) did not receive TXA. Outcome measures included BT rate, volume of transfused blood, deep vein thrombosis and occurrence of pulmonary embolism. RESULTS: BT rate was significantly less for the TXA group (37.5%) compared with the control group (65%; p=0.011). The mean blood volume transfused was also significantly less for the TXA group (240 mL) compared with the control group (450mL; p=0.009). No adverse events occurred in any group. Conclusons: Perioperative intravenous tranexamic acid is effective in reducing blood transfusion rate and volume of transfused blood, without increasing the risk of thromboembolic events in patients undergoing primary cementless total hip arthroplasty.

Long-term results of anti-protrusion cage and massive allografts for the management of periprosthetic acetabular bone loss.

From 1992 to 1995, 71 total hip arthroplasties with extensive acetabular bone loss underwent revision using bulk allografts and Burch-Schneider anti-protrusion cages. Twelve patients died of unrelated causes and 3 were lost to follow-up. Fifty-six hips were available for clinical and radiographic follow-up examination at an average of 11.7 years after surgery. The average final Harris hip score was 75. X-ray signs of incorporation of massive bone graft were observed in 49 hips. Two cases developed deep infection that required resection arthroplasty. Aseptic loosening of the acetabular cage occurred in 5 patients, and 2 of them underwent re-revision. With a total survival rate of 87.5%, anti-protrusion cages and structural allografts compare favorably with other techniques in the long-term reconstructive treatment of extensive loss of acetabular bone stock.