Low-Contact-Stress Knee Arthroplasty: Past History or Ahead of Time?

Low-contact-stress mobile-bearing (MB) total knee arthroplasty (TKA) can rely on a long history. Its concept comprises a combination of high condylar congruency and compensatory bearing rotation to promote load sharing. However, other MB designs have become available, and critical points have been raised about the benefit of MB in general. Although there is kinematic and kinetic support for the low-contact-stress concept, there is no tribologic or clinical proof of its superiority over fixed-bearing concepts. Further study should be controlled for differences in polyethylene quality and need to provide a measure of condylar congruency to differentiate authentic low-contact-stress variants form others. [Orthopedics. 2016; 39(3):e402-e412.].

Mobile-bearing total knee arthroplasty: More rotation is evident during more demanding tasks.

BACKGROUND: Some reports showed few but significant more axial femorotibial rotation in favor of mobile-bearing (MB) versus fixed-bearing (FB) total knee arthroplasty (TKA), mostly during knee bend fluoroscopic studies. The goal of the current study was to submit MB and FB groups of TKA patients to a turning activity, in which additional rotation was to be expected. METHODS: Two consecutive cohorts of patients after TKA (10 FB and 11 MB knees in a total of 18 patients) were assessed using motion analysis five year postoperatively, while performing gait and sit-to-walk (STW) movements with and without turning steps. RESULTS: Mean range of rotation in the FB group increased from 9.7° during gait, to 11.7° during STW straight, and to 14.3° during STW turning. Mean range of rotation in the MB group increased from 13.4° during gait to 21.0° during STW straight, and stayed at 21.1° during STW turning. CONCLUSIONS: Too many uncontrolled variables in the current study hinder a meaningful discrimination of MB from FB TKA rotation. However, the study does illustrate how more demanding task loads could be helpful in exploring the geometric constraints of TKA variants. LEVEL OF EVIDENCE: Level III, therapeutic study.

Patient blood management in elective total hip- and knee-replacement surgery (Part 1): a randomized controlled trial on erythropoietin and blood salvage as transfusion alternatives using a restrictive transfusion policy in erythropoietin-eligible patients.

BACKGROUND: Patient blood management combines the use of several transfusion alternatives. Integrated use of erythropoietin, cell saver, and/or postoperative drain reinfusion devices on allogeneic erythrocyte use was evaluated using a restrictive transfusion threshold. METHODS: In a factorial design, adult elective hip- and knee-surgery patients with hemoglobin levels 10 to 13 g/dl (n = 683) were randomized for erythropoietin or not, and subsequently for autologous reinfusion by cell saver or postoperative drain reinfusion devices or for no blood salvage device. Primary outcomes were mean allogeneic intra- and postoperative erythrocyte use and proportion of transfused patients (transfusion rate). Secondary outcome was cost-effectiveness. RESULTS: With erythropoietin (n = 339), mean erythrocyte use was 0.50 units (U)/patient and transfusion rate 16% while without (n = 344), these were 0.71 U/patient and 26%, respectively. Consequently, erythropoietin resulted in a nonsignificant 29% mean erythrocyte reduction (ratio, 0.71; 95% CI, 0.42 to 1.13) and 50% reduction of transfused patients (odds ratio, 0.5; 95% CI, 0.35 to 0.75). Erythropoietin increased costs by €785 per patient (95% CI, 262 to 1,309), that is, €7,300 per avoided transfusion (95% CI, 1,900 to 24,000). With autologous reinfusion, mean erythrocyte use was 0.65 U/patient and transfusion rate was 19% with erythropoietin (n = 214) and 0.76 U/patient and 29% without (n = 206). Compared with controls, autologous blood reinfusion did not result in erythrocyte reduction and increased costs by €537 per patient (95% CI, 45 to 1,030). CONCLUSIONS: In hip- and knee-replacement patients (hemoglobin level, 10 to 13 g/dl), even with a restrictive transfusion trigger, erythropoietin significantly avoids transfusion, however, at unacceptably high costs. Autologous blood salvage devices were not effective.

Patient blood management in elective total hip- and knee-replacement surgery (part 2): a randomized controlled trial on blood salvage as transfusion alternative using a restrictive transfusion policy in patients with a preoperative hemoglobin above 13 g/dl.

BACKGROUND: Patient blood management is introduced as a new concept that involves the combined use of transfusion alternatives. In elective adult total hip- or knee-replacement surgery patients, the authors conducted a large randomized study on the integrated use of erythropoietin, cell saver, and/or postoperative drain reinfusion devices (DRAIN) to evaluate allogeneic erythrocyte use, while applying a restrictive transfusion threshold. Patients with a preoperative hemoglobin level greater than 13 g/dl were ineligible for erythropoietin and evaluated for the effect of autologous blood reinfusion. METHODS: Patients were randomized between autologous reinfusion by cell saver or DRAIN or no blood salvage device. Primary outcomes were mean intra- and postoperative erythrocyte use and proportion of transfused patients (transfusion rate). Secondary outcome was cost-effectiveness. RESULTS: In 1,759 evaluated total hip- and knee-replacement surgery patients, the mean erythrocyte use was 0.19 (SD, 0.9) erythrocyte units/patient in the autologous group (n = 1,061) and 0.22 (0.9) erythrocyte units/patient in the control group (n = 698) (P = 0.64). The transfusion rate was 7.7% in the autologous group compared with 8.3% in the control group (P = 0.19). No difference in erythrocyte use was found between cell saver and DRAIN groups. Costs were increased by €298 per patient (95% CI, 76 to 520). CONCLUSION: In patients with preoperative hemoglobin levels greater than 13 g/dl, autologous intra- and postoperative blood salvage devices were not effective as transfusion alternatives: use of these devices did not reduce erythrocyte use and increased costs.

Cemented total hip arthroplasty in rheumatoid arthritis. A systematic review of the literature.

BACKGROUND: Cemented total hip arthroplasty (THA) in rheumatoid arthritis (RA) is allegedly associated with increased rates of infection, dislocation and aseptic loosening of cup and stem. METHOD: Systematic review of the literature on clinical and radiological results of cemented THA in RA. RESULTS: Twenty-one case series and eight reports on four implant registries were included. The quality of most studies was judged to be poor. The reported rates of infection and dislocation in the case series were conflicting with a risk of bias due to under-registration. The registries proved unsuitable for providing reliable data on the incidence of these two complications. Increased rates of aseptic loosening were reported in 10 out of 20 case series on the cup and in six out of 19 on the stem. Nearly all of these were based on series implanted before 1980. None of the registries reported a significantly increased risk of aseptic loosening of cup or stem. CONCLUSIONS: Considering the relatively frequent reports of increased infection rates in combination with the potential under-registration of complications, RA patients have to be considered to have a mild increased risk of postoperative infection. Case series and registries cannot answer the question of whether RA is a risk factor for dislocation as multivariate analysis is required. Increased rates of cup and stem failure due to aseptic loosening in RA patients are found in older but not in more recent studies.

Patients with severe radiographic osteoarthritis have a better prognosis in physical functioning after hip and knee replacement: a cohort-study.

INTRODUCTION: Although Total Hip and Knee Replacements (THR/TKR) improve Health-Related Quality of Life (HRQoL) at the group level, up to 30% of patients are dissatisfied after surgery due to unfulfilled expectations. We aimed to assess whether the pre-operative radiographic severity of osteoarthritis (OA) is related to the improvement in HRQoL after THR or TKR, both at the population and individual level. METHODS: In this multi-center observational cohort study, HRQoL of OA patients requiring THR or TKR was measured 2 weeks before surgery and at 2-5 years follow-up, using the Short-Form 36 (SF36). Additionally, we measured patient satisfaction on a 11-point Numeric Rating Scale (NRSS). The radiographic severity of OA was classified according to Kellgren and Lawrence (KL) by an independent experienced musculoskeletal radiologist, blinded for the outcome. We compared the mean improvement and probability of a relevant improvement (defined as a patients change score ≥ Minimal Clinically Important Difference) between patients with mild OA (KL Grade 0-2) and severe OA (KL Grade 3+4), whilst adjusting for confounders. RESULTS: Severe OA patients improved more and had a higher probability of a relevant improvement in physical functioning after both THR and TKR. For TKR patients with severe OA, larger improvements were found in General Health, Vitality and the Physical Component Summary Scale. The mean NRSS was also higher in severe OA TKR patients. DISCUSSION: Patients with severe OA have a better prognosis after THR and TKR than patients with mild OA. These findings might help to prevent dissatisfaction after THR and TKR by means of patient selection or expectation management.

Intra-abdominal migration of a lag screw in gamma nailing: report of a case.

An 83-year-old female patient was referred to the emergency room with progressive pain on mobilization. Three weeks before presentation, she had been treated with a gamma nail for an unstable right intertrochanteric fracture. Pelvic x-ray showed an intra-abdominally migrated lag screw. No evidence of intra-abdominal lesions was visible on computed tomographic scan. The lag screw as well as the intramedullary nail was extracted and in a second operation, a total hip arthroplasty was implanted. Unfortunately, the total hip implant dislocated and needed reduction. The three consecutive operations seriously weakened the soft tissue envelope. A plaster cast and brace, immobilizing the right hip and pelvis, were provided to prevent recurrences of dislocation. After 6 weeks of immobilization, the patient did well. No late complication occurred. A review of the literature with an emphasis on pathophysiology of intra-abdominal or retroperitoneal migration of lag screws in gamma nailing is presented.

Construct validity and reliability of the disability of arm, shoulder and hand questionnaire for upper extremity complaints in rheumatoid arthritis.

OBJECTIVE: The Disability of Arm, Shoulder and Hand (DASH) questionnaire is a tool for measuring physical function and symptoms of the upper extremity. Although widely used, it is not validated for rheumatoid arthritis (RA). In this study the DASH was validated for this patient group. METHODS: In total, 102 patients participated in this study. For the validation, the questionnaires of the DASH, the Health Assessment Questionnaire (HAQ), the Medical Outcomes Study Short Form-36 (SF-36), and the Arthritis Impact Measurement Scale (AIMS2) were used. Patients were examined clinically before completing the questionnaires. Pain was scored by each patient using a visual analog scale (VAS). The Disease Activity Score (DAS28) was obtained and grip strength was measured. Reliability was tested by a second DASH questionnaire after 2 days. Validity was tested using a Pearson correlation analysis for the relevant domains of the questionnaires and for the clinical aspects. RESULTS: The reliability of the DASH was excellent (intraclass correlation coefficient 0.97). Internal consistency was strong (Cronbach's alpha 0.97). Validity was proven with excellent results for Pearson correlation with the relevant domains of the questionnaires: HAQ, r = 0.88; SF-36, r = 0.70; and AIMS2, r = 0.85. The clinical scores had a relatively low correlation with the DASH (DAS28, r = 0.42; and grip strength, r = 0.41-0.48), except for the VAS (r = 0.60-0.65). CONCLUSION: The DASH is a reliable and valid questionnaire in patients with RA. It can be used as a measurement tool of physical disability of the upper extremity.

Scarf osteotomy in hallux valgus: a review of 72 cases.

The Scarf osteotomy is now widely used for the correction of hallux valgus. The aim of our study was to evaluate the results after Scarf osteotomy considering patient's satisfaction as well as the clinical and radiological results. Between 1996 and 1999, 72 feet underwent a Scarf osteotomy of the first metatarsal and, in 11 feet, an additional Akin osteotomy of the proximal phalanx, for the correction of hallux valgus (55 patients: 49 female, 6 male; mean age: 52 years). The hallux valgus angle improved significantly, from 32 degrees preoperatively to 18 degrees at follow-up (minimal follow-up: 6 years; mean: 7.5 years). A second operation was necessary in two patients because of recurrence of hallux valgus, and a fusion of the first metatarsophalangeal joint was performed in two patients. At the time of latest follow-up 78% of the patients were satisfied or very satisfied with the result. The Scarf osteotomy combined with Akin's closing wedge osteotomy is a safe and effective procedure for the treatment of moderate hallux valgus deformities.

Factors associated with excessive migration in bone impaction hip revision surgery: a radiostereometric analysis study.

A prospective radiostereometric analysis (RSA) study of 18 patients with cemented revision hip surgery and impaction grafting with an Exeter stem was done with a follow-up of 2 years for all patients. All factors that could influence migration (ie, micromotion) of the stem were analyzed with a repeated measurements analysis of variance. Two groups could be identified: a stable group and a continuous migrating group. Two factors significantly influenced micromotion during the follow-up measurements. The first factor was the Paprosky classification (the bigger the defect, the higher the micromotion). The second factor was cement mantle defects in > or =1 Gruen zones. The migrating hip stems had more Gruen zones with cement mantle defects (45%) compared with the stable prostheses (21%). The effect of the first factor on micromotion was limited and probably clinically less relevant. Because the cement mantle defects found in this study were caused by poor instrumentation, the second factor stresses the importance of good instrumentation, which is essential to make this technically demanding technique effective in creating a stable stem-allograft construct in the defective femoral canal.