Prospective multicentre mid-term clinical and radiological outcomes of 159 reverse total shoulder replacements and assessment of the influence of post-operative complications.

Background: The aim of our prospective multicentre study is to evaluate the five-year follow-up outcomes of primary reverse shoulder replacement utilizing two different designs of glenoid baseplates. Methods: There were 159 reverse shoulder replacements (91 cemented and 68 uncemented stems, 67 Trabecular Metal baseplates and 92 Anatomical Shoulder baseplates in 152 patients (99 women) with a mean age of 74.5 (58-90) years. The principal diagnosis was rotator cuff arthropathy in 108 shoulders. Results: Clinical and functional results improved significantly overall; the adjusted Constant Murley score improved from 28.2 ± 13.3 pre-operatively to 75.5 ± 22.8 (p < 0.0001) and the mean Subjective Shoulder Value improved from 27.5 ± 20 to 73.8 ± 21.3 points (p < 0.0001). Radiologically, there was good bony stability in 88% and 86% of cemented and uncemented stems without significant impact on the Constant Murley score and Subjective Shoulder Value at one, two and five years post-surgery. There were no significant clinical differences between Trabecular Metal and Anatomical Shoulder baseplates at five years. There were four cases of intraoperative shaft fractures that were managed with cables. Although the Trabecular Metal baseplates showed better integration radiologically, there was no significant difference in the mean of Constant Murley, Subjective Shoulder Value and the range of motion depending on the grade of inferior scapular notching at one-, two- and five-year intervals. Conclusions: Reverse total shoulder arthroplasty restores the function in shoulder with significant improvements in function and moderate complications with minor differences between both designs of baseplates that were not reflected clinically.

Incidence of heterotopic ossification in minimally invasive short-stem THA using the modified anterolateral approach.

INTRODUCTION: Heterotopic ossification (HO) is known to be a common complication after total hip arthroplasty (THA). The minimal invasive (MIS) modified anterolateral approach has become popular in combination with a short stem. We analysed the incidence of HO following short-stem THA using this approach in combination with a postoperative administration of nonsteroidal anti-inflammatory drugs (NSAIDs). MATERIALS AND METHODS: 216 short stems were implanted in 162 patients. NSAIDs were administered for 2 weeks after surgery in 154 patients (95.1%). Standardised pre- and postoperative radiographic imaging was done at 2-year follow-up. HO was analysed according to the Brooker classification. Influence of age, gender, body mass index (BMI), and blood transfusion were analysed. Harris Hip Score (HHS) and visual analogue scale (VAS) of satisfaction were assessed. Operation time and blood-transfusion rate was documented. Short-term gastrointestinal side effects were recorded. RESULTS: The overall incidence of HO was 7.8% (16 cases). HO Brooker type 3 and 4 occurred in only 1 case (0.5%). No correlation with age, gender or BMI was revealed. HHS improved largely from 45.8 (SD 15.9) before surgery to 98.1 (SD 4.7) after a minimum of 2 years. At that point VAS satisfaction was 9.7 (SD 0.9). Mean operative time was 45.8 minutes (SD 18.7). 12 patients (7.4%) received at least 1 blood-transfusion. Gastrointestinal side effects occurred in 13 of 154 patients (8.4%). CONCLUSIONS: The combination of short-stem THA, the MIS modified anterolateral approach and a postoperative application of NSAIDs resulted in the effective prevention of HO and excellent clinical results.

The use of polycarbonate-urethane as an acetabular shell bearing surface: a 5-year prospective study.

AIM: To evaluate the clinical performance of a polycarbonate-urethane liner as a bearing material inside a cobalt-chrome acetabular shell. METHODS: Between December 2007 and July 2011, this material combination was used in 27 total hip replacement patients, most of whom had an indication of osteoarthritis. This report focuses on the first 5-year results of the clinical use of this material combination in the TriboFit® Hip System. RESULTS: Mean Harris Hip Score showed significant improvement from 40 to 86 after 5 years, similar to studies in the literature. No adverse events - revisions or complications - or disadvantages that have been reported for other total hip materials were observed over the 5-year period. The radiographs showed no signs of wear, migration or loosening of the implants. CONCLUSIONS: These early results indicate this new material combination offers promise as a safe and effective alternative bearing material for use in total hip systems. Further clinical trials are necessary to reconfirm these findings.

Radiographic alterations in short-stem total hip arthroplasty: a 2-year follow-up study of 216 cases.

INTRODUCTION: In recent years a variety of short-stems have been introduced. Stable osteointegration is a key factor for a satisfactory long-term result. The purpose of this study was to evaluate postoperative radiological alterations and subsidence, as a result of using a newly developed device, over a 2-year follow-up. METHODS: 216 short-stems were implanted in combination with a cementless cup. Patients were allowed full weight-bearing on the first day postoperatively. Pre- and postoperative x-rays were done using a standardised technique. Radiological alterations, such as bone resorption, radiolucency, osteolysis and cortical hypertrophy were detected and located using modified Gruen zones, and subsidence was measured via a conventional digital technique over a 2-year follow-up. In addition, Harris Hip Score (HHS), rest pain and load pain on the visual analogue scale (VAS) were assessed respectively. RESULTS: At 2-year follow-up 6 stems (2.9%) showed nonprogressive radiolucent lines with a maximum width of 2 mm. Resorption of femoral bone stock was detected in a total of 8 cases (3.9%). Femoral cortical hypertrophy was seen in a total of 9 hips (4.4%). No patient showed osteolysis. A measureable subsidence of at least 2 mm was observed in a total of 15.7% (32 cases) after 6 weeks, corresponding to an initial settlement given full weight-bearing ambulation. Only 1.1% (2 cases) showed further progression at the 6-month follow-up, whereas at the 1- and 2-year follow-ups no further subsidence was observed. After 2 years HHS was 98.1 (65.0-100.0), rest pain on the VAS was 0.2 (0.0-7.0) while load pain was 0.4 (0.0-7.0). CONCLUSIONS: The results of this radiographic analysis give support to the principle of using metaphyseal anchoring, calcar guided short-stems. The low incidence of bony alterations after a follow-up of 2 years indicates a physiological load distribution. After mild initial subsidence a stable osteointegration can be achieved over time.

The Basis CL cemented femoral stem: results after 8.9 years follow-up.

This prospective study was conducted to demonstrate that the matte-finish Basis CL cemented endoprosthetic stem delivers good qualitative results after 10 years. Between January and December 1999, 205 consecutive hips (201 patients; 74.5 ± 6.8 years at surgery) underwent primary total hip arthroplasty with the Basis CL and the same acetabular cup (RM Classic cup) at a single institution. Follow-up data at 10 years was available for 120 hips (average follow-up of 8.9 years, ±2.9). Mean Harris Hip Score improved from 39.5 ± 16.8 at baseline to 75.9 ± 16.7 at 10-year follow-up (p<0.001). Four hips required revision during the study: three for infection and one for pain. There were no cases of aseptic loosening, implant migration, or stem fracture. Cumulative survival at 10 years was 97.4% with the endpoint of revision for any reason. In conclusion, results with the matte-finish cemented Basis CL indicated that it was safe and effective after medium-term follow-up.

Treatment for acetabular dysplasia using the uncemented RM acetabular component - a 20 year follow-up.

Our study reports a sub-group of patients with developmental dysplasia from a previously published larger series, with particular emphasis on the use of the uncemented RM acetabular component. We evaluated the long term results of 93 consecutive uncemented THAs in 80 patients using the titanium-coated RM acetabular component and the CLS femoral component in a prospective study. Eighteen hips in 16 patients had osteoarthritis secondary to developmental dysplasia of the hip. The mean follow-up was 19.6 years (18.2 to 20.9). Fourteen patients with 15 hips were clinically and radiographically examined and evaluated. Two patients with 3 hips died. No patient was lost to follow-up. No implant had to be revised, and no cases showed evidence of radiographic loosening. Nine acetabular components were not completely covered by host bone but this did not affect the outcome. At the latest follow-up the mean Harris Hip Score was 92 (81 to 100). The mean annual wear rate was 0.12 mm. The RM acetabular component performed well over 20 years in this selected group of patients. Complete acetabular containment was not needed, thus allowing reliable reconstruction of the anatomical centre of rotation.

Treatment for acetabular dysplasia using the uncemented RM acetabular component - a 20 year follow-up.

Our study reports a sub-group of patients with developmental dysplasia from a previously published larger series, with particular emphasis on the use of the uncemented RM acetabular component. We evaluated the long term results of 93 consecutive uncemented THAs in 80 patients using the titanium-coated RM acetabular component and the CLS femoral component in a prospective study. Eighteen hips in 16 patients had osteoarthritis secondary to developmental dysplasia of the hip. The mean follow-up was 19.6 years (18.2 to 20.9). Fourteen patients with 15 hips were clinically and radiographically examined and evaluated. Two patients with 3 hips died. No patient was lost to follow-up. No implant had to be revised, and no cases showed evidence of radiographic loosening. Nine acetabular components were not completely covered by host bone but this did not affect the outcome. At the latest follow-up the mean Harris Hip Score was 92 (81 to 100). The mean annual wear rate was 0.12 mm. The RM acetabular component performed well over 20 years in this selected group of patients. Complete acetabular containment was not needed, thus allowing reliable reconstruction of the anatomical centre of rotation.

A two-year prospective and retrospective multi-center study of the TriboFit® Hip System.

The first 50 cases using a polycarbonate-urethane acetabular component in the TriboFit® Hip System for human hip reconstruction were reviewed. The average follow-up for cases not revised or deceased prior to 24 months was 28.0 months. The clinical results were similar to those reported in the literature for the same indications and follow-up. Therefore, with 2 to 4 years follow-up, it can be concluded that the TriboFit® Hip System is as safe and effective for use as a hip replacement system in femoral neck fracture patients as traditional hemiarthroplasty systems, and in osteoarthritis patients as a total hip system made of traditional bearing materials.

Retrieval analysis of a polycarbonate-urethane acetabular cup: a case report.

An acetabular cup made of a compliant polycarbonate-urethane material has been introduced as an alternative bearing solution. This case study examines the use of this acetabular cup in a single patient at 12 months. The cup had minimal loss of thickness with the most being in the superior area (approximately 10%) and minimal loss of weight (2.4%). On the back side was evidence of abrasive macroscopic wear on one side of the implanted component in the area of directional loading from the head to the acetabulum. On the front side, the wear rate was determined to be minimal (less than 15 mm3 per year), meaning that most of the change in thickness and weight was caused on the back side. The retrieved synovial fluid appeared normal in color and volume at the time of revision. The histology of the tissue taken showed minimal wear particles and minimal reactivity, confirming that the patient did not have any signs of synovitis.The analysis of the cup confirms the preclinically determined low wear articulation and biocompatibility of polycarbonate-urethane as a weight-bearing material. In summary, the surgical findings, data reviewed, and images taken from this case report warrant further study.

Technique and first clinical results of robot-assisted total knee replacement.

Total knee replacement (TKR) is a common procedure for treatment of severe gonarthrosis, but the outcome may be unsatisfactory due to primary malalignment of the prosthetic components. In order to improve precision and accuracy of this surgical procedure, a commercial robotic surgical system (CASPAR) has been adapted to assist the surgeon in the preoperative planning and intraoperative execution of TKR. So far, 70 patients with idiopathic gonarthrosis were successfully treated with a robot-assisted technique in our institution. No major adverse events related to the use of the robotic system have been observed. The mean difference between preoperatively planned and postoperatively achieved tibiofemoral alignment was 0.8 degrees (0-4.1 degrees ) in the robotic group vs. 2.6 degrees (0-7 degrees ) in a manually operated historical control group of 50 patients. A clear advantage of robot-assisted TKR seems to be the ability to execute a highly precise preoperative plan based on computed tomography (CT) scans. Due to better alignment of the prosthetic components and improved bone-implant fit, implant loosening is anticipated to be diminished which may be most evident in non-cemented prostheses. Current disadvantages such as the need for placement of fiducial markers, increased operating times and higher overall costs have to be resolved in the future.